The story, which contains excerpts from The Hitchhiker’s Guide to the Galaxy (The Guide) as well as the story’s plot, opens with The Guide’s slightly condescending description of Earth and its primitive, ape-descended inhabitants. The beings of Earth are described as mean, overwhelmed by problems, obsessed with green paper, and living out a miserable existence. The narrator then explains how a girl, sitting in a café, has a sudden epiphany about how to make everything better; however, before she can relay this world-changing idea, an undescribed catastrophe occurs.
The narrator points out that the story to come is not about her but about the catastrophe and its consequences as well as a book titled The Hitchhiker’s Guide to the Galaxy, which is described as a text that no Earthman has ever seen. The Guide, one of the most popular books in the galaxy, possibly contains information that is not entirely true, however. The book’s success is ascribed to its low cost and the appearance of the words “Don’t Panic” on its cover. As the introduction concludes, the narrator states that The Guide plays a major role in events that surround the aforementioned catastrophe, which all begin at a house.
Arthur Dent is an anxious thirty-year-old man who lives in a small house in England. One morning, Arthur awakes and sees a bulldozer outside his home as the local council wishes to demolish Arthur’s house to build a bypass. Suddenly, Arthur finds himself lying down in the mud in front of the machine. Mr. Prosser, the manager in charge of the demolition crew, complains that the plans have been available for Arthur to protest for several months, but Arthur only learned about the council’s decision the day before.
Ford Prefect, one of Arthur’s closest friends, suddenly appears and urges Arthur come to the pub for drink. While Ford’s Earth friends believe that he is an out-of-work actor, he is really a researcher for The Hitchhiker’s Guide to the Galaxy and is from another planet. Ignoring Arthur’s predicament, Ford insists that he has something important to tell Arthur, but Arthur refuses to leave. Ford somehow convinces Mr. Prosser to take Arthur’s place in front of the bulldozer, and the two head to the Horse and Groom, leaving a humiliated Mr. Prosser behind.
Chapter 2 opens with The Guide’s description of alcohol and quickly digresses into a detailed entry regarding the Pan Galactic Gargle Blaster, which explains its effects, how it is made, and where to get the best one in the galaxy.
Ford and Arthur are now in the pub known as the Horse and Groom. As Ford orders six pints of beer, he begins talking to the friendly bartender and suggests that the Earth will be ending in ten minutes. He then encourages Arthur to drink up his three pints quickly, as the alcohol will act as a muscle relaxant. When Arthur begins to question him, Ford reveals his true origins, explaining that he is really from a planet near Betelgeuse. Arthur is incredulous. Ford then announces that the world is about to end, which elicits an awkward moment between Arthur and the rest of the pub that ends with Arthur lamenting over his inability to deal with Thursdays.
As Arthur struggles to finish his third pint, he hears the crash of the bulldozer knocking down his house. Arthur runs out of the bar screaming, and Ford follows him, knowing that a Vogon Constructor fleet is descending on the planet. Arthur shouts for the construction crew to stop and stumbles to the ground, finally seeing the giant yellow starships descending from the sky.
The Earth suddenly becomes silent as the Vogon fleet hangs in the air. Without warning, every audio device on the planet transmits the voice of Prostetnic Vogon Jeltz of the Galactic Hyperspace Planning Council bureaucratically informing the people of Earth that their planet has been scheduled for demolition to make way for a hyperspatial express route. The impassive voice announces that the process will only take two Earth minutes. Panic ensues, and, annoyed, Jeltz suggests that since the plans have been available for viewing for the past fifty years on Alpha Centauri, which is only four light-years away, the people have no right to act surprised. After conferring with someone on Earth, Jeltz orders his men to destroy the planet.
Zaphod Beeblebrox, the three-armed, two-headed, impetuous President of the Imperial Galactic Government, a position that is described in a long footnote as being entirely ceremonial, races across the planet Damogran in a speedboat heading for a ceremony where he will ceremoniously reveal the new, sleek starship the Heart of Gold, named such as it contains a special golden box at its center. Zaphod performs his job well due to his flashy character and ability to attract attention to himself, which is exactly how he approaches the platform filled with cameras and a crowd of people who are waiting for him to reveal the Heart of Gold to the galaxy.
On the platform, Zaphod ignores the speech given in his honor but says hello to Trillian, a petite, dark-haired humanoid who Zaphod picked up on a small planet. The speech over, Zaphod dismissively greets the crowd and flicks a switch that opens a large dome, revealing the Heart of Gold. Only moments later, Zaphod winks at Trillian and boldly informs his galaxy-wide audience that he plans to steal the Heart of Gold. Zaphod then lets out a triumphant “Whoop!” as he drops a Paralyso-Matic bomb, which freezes the crowd in place.
The Vogons are a destructive, thickheaded, slow-minded race who play an important part of the Galactic Civil Service. Jeltz—a typical Vogon—does not like hitchhikers. Ford and Arthur find themselves on Jeltz’s starship, having been picked up by the Dentrassis, a race who work as caterers on the Vogon starship. As Arthur comes to, Ford attempts to explains how he used his Electronic Thumb to get them a lift on one of the Vogon starships. Ford shows Arthur how to use The Guide by looking up the entry on Vogons. Then Ford explains how he became stranded on Earth for fifteen years while doing research for the book’s new edition.
When Ford explains to Arthur that the Vogons destroyed the Earth, Arthur begins to panic, so Ford points out the advice “Don’t Panic” written on The Guide’s cover. Ford then informs Arthur that he is welcome to join Ford on his adventures. Suddenly, a harsh and violent noise issues from the loudspeaker, stunning Arthur. Ford takes the opportunity to stick a translation device—a small yellow fish—in Arthur’s ear, and the harsh garbles suddenly translate into perfect English.
Over the loudspeaker, Jeltz announces that he is aware of the two hitchhikers onboard—Ford and Arthur—and has sent a search party to find them and throw them off the starship, adding that he might read them some poetry before they depart. Jeltz then explains that once the hitchhikers are gone, the starship will enter hyperspace and head to Barnard’s Star. As Ford and Arthur prepare for hyperspace travel, Ford tells Arthur that the fish he put in his ear is called a Babel fish, and he suggests that Arthur look it up in The Guide.
As the starship passes through hyperspace, Arthur reads the entry on Babel fish and learns that they are incredibly useful as they feed off brain waves and telepathically translate any speech patterns heard. Amazed that he survived the hyperspace jump, Arthur realizes how far he is from where Earth used to be, and he attempts to come to terms with the fact that the Earth is gone. Curious, Arthur looks up the entry for “Earth” in The Guide. To his amazement, the entry consists of only one word: “harmless.” Suddenly, Arthur and Ford hear the search party in the hall, and Ford worries that Jeltz will make good on his promise to read them poetry.
Vogon poetry is described as the third worst kind of poetry in the galaxy, and Jeltz uses his verse to torture the now-captive Ford and Arthur, who have been strapped in Poetry Appreciation chairs. After reciting a few agonizing lines and watching Ford and Arthur squirm, Jeltz offers them a choice: They can be thrown out into space, or they can tell him how good his poetry is. While Ford stumbles to speak, Arthur provides a lengthy analytical critique of Jeltz’s poem, which Jeltz proclaims is incorrect; he then orders both men to be taken to an airlock and thrown off the starship.
As a large Vogon drags Ford and Arthur through the halls to the airlock, constantly exclaiming that their resistance is useless, Ford and Arthur attempt to convince him of the meaninglessness of his job. Noting that they have almost gotten through to the Vogon, Ford and Arthur suggest that he should be doing something important with his life. Ultimately, the Vogon rejects their ideas and pushes them into the airlock. Incredulous about their current predicament, Arthur realizes that every memory of Earth will die with him as he and Ford are shot out into space.
Chapter 8 opens with the introduction to The Hitchhiker’s Guide to the Galaxy (The Guide), which describes the incomprehensible vastness of space, adding that space is so vast, even light takes time to travel through it. The Guide also advises that while taking in a lungful of air allows a person to survive for thirty seconds in the vacuum of space, space is so large that the chances of being rescued in that thirty-second span of time are two to the power of 276,709 to one against. This number is coincidentally the phone number of a young woman who Arthur once tried to pick up on Earth, though he failed miserably and she ended up leaving with a mysterious party crasher. Despite the staggering, nearly impossible odds, Arthur and Ford are rescued twenty-nine seconds after being ejected into space.
A computer alarm sounds as the Heart of Gold’s airlock opens to pick up Ford and Arthur. The Infinite Improbability Drive, which powers the starship, causes a small hole to briefly open in the Galaxy, and several random items fall out of it, including balloons and several three-foot-tall market analysts. As they come to their senses, Ford and Arthur find themselves in a seemingly impossible environment. They both see several curious sights including a five-headed man and a kipper-filled bush. A disembodied voice suddenly announces a measurement of probability as Arthur’s body begins to warp with the fabric of time and Ford turns into a penguin. Ford begins to quack questions at the starship’s computer. The computer responds to Ford’s questions by asserting that he and Arthur are safe on the Heart of Gold. The computer explains that Ford and Arthur are experiencing the effects of the improbability level of their rescue, but that level is now slowly returning to normal.
Excitedly, Ford informs Arthur that they have been picked up by a starship powered by a propulsion system only rumored to exist—the Infinite Improbability Drive. Suddenly, they find themselves in a pink cubicle confronted by a multitude of monkeys who wish to discuss a script they wrote for Hamlet.
Chapter 10 details the strange and curious history of the Infinite Improbability Drive. A physics student conceptualized the propulsion system while sweeping up the lab after a party. The student thought that since it was nearly impossible to create an Infinite Improbability Drive, then there must be a finite improbability that such a thing could be created. The student then figured out the exact improbability and entered that number, as well as a fresh cup of hot tea, into the finite improbability generator, an invention previously used for lewd party tricks. This process, against all probability, created the golden Infinite Improbability Drive, which now powers the Heart of Gold. The student received an award for his cleverness, only to be lynched by a group of angry physicists who thought he was a know-it-all.
Zaphod paces the Heart of Gold’s improbability-proof cabin, concerned about the hitchhikers—Ford and Arthur—as Trillian calls out decreasing probabilities, finally reaching normality. Zaphod argues about the morality and recklessness of picking up hitchhikers with Trillian, when she points out that the starship picked them up on its own. Zaphod orders Marvin, the severely depressed and nihilistic robot that came with the starship, to retrieve Ford and Arthur.
Back to Ford and Arthur: The pink cubicle and monkeys suddenly disappear, and they find themselves in the starship’s embarkation area. Finding the starship’s sales brochure and flipping through the pages, Ford learns about the Infinite Improbability Drive and the fact that the starship is equipped with GPP, a Genuine People Personalities cybernetics computer. Just then, Marvin walks in, agrees with Arthur’s negative comments regarding the GPP, and, mimicking the sales brochure’s text, mockingly explains the dreadfully sunny disposition held by the starship’s computer. Marvin then escorts Ford and Arthur through the starship, complaining about the cheerful doors as they walk to the bridge. On the way, Ford asks which government owns the starship, and Marvin informs him that the starship has been stolen by Zaphod Beeblebrox. Astonished, Ford repeats the name.
On the bridge, Zaphod painstakingly works the starship’s radio, searching for news about himself, when Trillian, musing about Zaphod’s complex degrees of stupidity and cleverness, interrupts him. She points out that the starship picked up the hitchhikers in the same galaxy where he and Trillian met. Avoiding the annoyingly cheerful computer named Eddie, Zaphod tries to calculate the probability of such an occurrence and figures out that the odds are infinitely small. He then asks the computer to compile more improbability data, to which the computer responds that telephone numbers govern most people’s lives. Trillian, finding this to be an odd fact, turns on the starship’s monitors so she and Zaphod can see the two hitchhikers before they enter the bridge.
Marvin, complaining about his miserable, purposeless life, leads Ford and Arthur to the bridge. As they walk, Ford keeps repeating Zaphod’s name aloud, acting strangely and giggling. When Ford and Arthur finally enter the bridge, Zaphod, lounging back with his feet on a control panel, nonchalantly greets Ford by name. Ford coolly returns the greeting and introduces an astonished Arthur. As Ford begins to introduce his semi-cousin Zaphod to Arthur, Arthur interrupts him, explaining that the two have already met. Arthur then describes how, six months earlier, he was trying to pick up a beautiful, intelligent young woman at a party, when Zaphod, who called himself Phil, inferring that Arthur was boring the young woman, burst in and announced that he was from another planet. As Arthur laments his loss, Trillian flashes a knowing smile at Arthur and reveals that Zaphod was telling the truth. Recognizing Trillian as Tricia McMillian, the woman he attempted to meet at the party, Arthur asks her why she is here. Trillian explains that she hitched a ride with Zaphod. Suddenly, Zaphod groans and asks if this type of thing will happen every time they use the Improbability Drive, to which Trillian replies that most likely, it will.
Trillian, Zaphod, and Ford can’t sleep as each contemplates different dilemmas. Trillian reflects on the destruction of Earth and all that was lost there, and she considers the two small white mice that she forced Zaphod to allow her to bring with her into space. Zaphod struggles with a nagging feeling that he is missing something, a feeling that has been with him for a while but has been exacerbated by Ford’s and Arthur’s presence as well as the recent coincidences. Ford can’t sleep simply because he feels excited to be back on the road after being stuck on Earth.
Later, while Trillian enters Zaphod’s chamber to inform him that they may have found what he has been looking for, Ford, still unable to sleep, attempts to write an entry for The Guide. When Ford realizes he’s too anxious to write, he makes his way to the bridge to find Trillian and Zaphod staring at a black monitor. After cryptically leading Ford through a series of questions that allow him to deduce that they are currently in the Horsehead Nebula, Zaphod reveals two red stars that should not be there. Zaphod then triumphantly declares that he’s found the most improbable planet to ever exist.
Chapter 15 opens with an excerpt from The Guide on the planet Magrathea. The excerpt states that in ancient times the galaxy became very prosperous and that, as a result, many people became exceedingly wealthy. Wealth made many of these people feel bored with their lives, a condition the people believed to be caused by the planet they lived on. To remedy the situation, a special industry that focused on building luxury, customized planets was developed on the planet Magrathea. This industry became so popular that Magrathea quickly became the wealthiest planet in the galaxy. As Magrathea flourished, however, the rest of the galaxy became impoverished, which in turn led to the downfall of Magrathea. In the millions of years since its existence, Magrathea turned into a legend that no one believed anymore.
Arthur awakens and makes his way to the bridge, where he finds Ford and Zaphod arguing about the existence of Magrathea. Zaphod claims that the planet with the binary red stars that they are currently orbiting is the legendary Magrathea, while Ford argues that Zaphod could call any planet Magrathea and nobody would know whether he was correct. Confused about what he’s hearing, Arthur approaches Trillian for clarification. Trillian explains the nature of the argument, likening Magrathea to Earth’s Atlantis. Ford, beginning to doubt his position, asks Zaphod why he’s so fixated on finding Magrathea. Zaphod, in his typical manner, unconvincingly responds that he simply wants the fame and money that go with finding Magrathea.
When Arthur comments that the suspense is too much for him to handle, the narrator states that stress has become a major social problem and reveals that the planet is, in fact, Magrathea. The narrator adds that Magrathea’s defense system is about to launch a missile attack on the starship, but the damage will be minor.
As Arthur voices concern about their safety, an ancient recording plays, thanking them for coming to Magrathea and informing them that the planet is closed. Undeterred by the message, Zaphod commands Eddie, the starship’s computer, to keep flying toward Magrathea, which triggers another message from Magrathea that assures the occupants on the starship that they will be informed when Magrathea reopens and menacingly asks them to leave. Ignoring the warning, Zaphod tells the computer to begin the starship’s descent to Magrathea’s surface, which triggers a third message from Magrathea, assuring them that the nuclear missiles headed their way are reserved for only the “most enthusiastic clients.”
With this announcement, chaos ensues on the starship. Ford takes evasive maneuvers, which causes Zaphod to break a lever on the guidance system, which results in Ford’s copy of The Guide to fly out of his pocket and hit a console, which turns off the starship’s engines. Eddie counts down the time until the missiles strike, and Zaphod asks the computer to turn the engines back on and level the starship out. Eddie successfully follows both orders, all while singing “You’ll Never Walk Alone.” As the missiles hurl toward the starship, in an act of desperation, Arthur turns on the Infinite Improbability Drive.
The use of the Infinite Improbability Drive results in several transformations to the Heart of Gold’s cabin, including the addition of marble-topped tables, a wicker chair, and a small fishpond. Attempting to decipher the new instrument panels, which now can only be read by looking at them from the correct angle in a mirror, Trillian finds that they are still positioned above Magrathea, and Ford discovers that the missiles turned into a bowl of petunias and a whale. Zaphod commends Arthur for his quick thinking and saving their lives. When Arthur mentions that “it was nothing really,” Zaphod interprets his response literally and stops praising him. The narrative shifts to detail the improbable and very sudden appearance of a sperm whale popping into existence above Magrathea and then provides a complete record of the whale’s existential thoughts as it falls to its death.
The starship lands on the surface of Magrathea. Zaphod, Trillian, Ford, and Arthur—or, the crew—discuss whether to bring Marvin with them as they explore the planet. Suddenly, Trillian announces that her two white mice are missing. When Zaphod rudely dismisses the fact that the mice are missing as trivial, the narrator remarks that this event would be more interesting if he and the others knew that humans where actually the third most intelligent creatures on Earth. Eddie, now set to its backup, matriarchal personality, wishes them well, suggests they bundle up before exploring a new planet, and warns them not to play with alien monsters. Zaphod must threaten the computer before it finally opens the hatch to let them out. A short time later, Eddie opens the hatchway again after receiving an unexpected command to do so.
The crew discovers the crater made by the sperm whale’s impact, and Zaphod uncovers an entrance to the planet’s interior. Nervous about entering, since the planet already tried to kill them once, Zaphod asks Arthur to stay behind to guard the entrance with Marvin, who promptly turns himself off. As Zaphod, Ford, and Trillian walk down the Magrathean corridors, Zaphod reluctantly reveals that he often gets random urges to do things, like run for Galactic President, steal the Heart of Gold, and look for Magrathea, and somehow everything he does works out. Zaphod adds that when he tries to reflect about why he wants something, he finds thinking about the very thing difficult. Concerned that someone had purposefully locked off part of his mind, Zaphod explains how he visited the starship’s medical bay last night and ran a series of tests. He then revealed that he learned that the “someone” who locked off part of his mind was himself: He had cauterized the synapses in a part of his brain to prevent himself from knowing why he wanted to come to Magrathea. Suddenly, a steel door slams shut behind Zaphod, Trillian, and Ford, and a gas pours in, which causes them to pass out.
While waiting on the surface of Magrathea, Arthur reads random entries from The Guide. He reads about Veet Voojagig, who, after drinking Pan Galactic Gargle Blasters with Zaphod Beeblebrox, became obsessed with finding all of the lost ballpoint pens in the universe. After extensive research, Voojagig theorized that all of the lost ballpoint pens ended up on a planet somewhere in the galaxy. Later, Voojagig claimed to have spent time working as a limousine driver on that planet and wrote a book about his experience. Later, a small asteroid inhabited by a single man was discovered where Voojagig claimed the ballpoint pen world to be. The entry concludes by noting that Zaphod owns a lucrative secondhand ballpoint pen business. Tired of reading, Arthur wakes up Marvin and tries to talk with him. However, Marvin’s depressing and nihilistic demeanor is more than Arthur can take, so Arthur takes a walk instead. As night descends on Magrathea, the planet grows dark, and Arthur almost walks into an old man.
The old man, dressed in a long gray robe, watches two suns set over the horizon before finally acknowledging Arthur’s presence. He assuages Arthur’s initial trepidations when he explains that he has no intention of harming Arthur and that the missile attack was the result of the long-dormant and listless computer system attempting to find some excitement. Arthur admits he’s surprised to find a man on the planet, as he believed everyone on Magrathea was long dead. The old man then informs Arthur about the collapse of the Galactic economy. He explains that since custom planets were a luxury commodity, the Magratheans decided to sleep until the economy recovered enough for people to afford their services again.
The old man then asks about Marvin. After Arthur explains Marvin’s sulking demeanor, the old man suggests they leave him behind. The old man then asks Arthur his name and insists Arthur come with him in his aircar to journey into Magrathea’s interior. Arthur complies and asks the old man his name. Hesitant to respond, the old man tells Arthur that his name is Slartibartfast, which Arthur, nearly choking, makes him repeat.
The narrator reveals that because of man’s amazing inventions and achievements, man always believed that he was the smartest creature on Earth. However, dolphins have always believed themselves to be smarter than man. For example, dolphins knew about the imminent threat to Earth by the Vogon fleet and had even attempted to warn man about it, but man misinterpreted the dolphins’ attempts to communicate as elaborate tricks. Consequently, dolphins decided to leave Earth before its destruction, parting with the final “thank you” to the humans for all the fish humans fed them over the years. The narrator continues to explain that there was one species on Earth that was even smarter than the dolphins and that this species conducted elaborate experiments on man for centuries.
Slartibartfast and Arthur race across Magrathea and through a series of tunnels that bring them to the center of the planet. They arrive at a seemingly infinite area of space with an enormous, shimmering wall. Slartibartfast informs Arthur that they’ve arrived on the factory floor and that the Magratheans have been awoken to fulfill one commission for a special, pandimensional client. A light reveals a large, familiar-looking planet, which is to be Earth Mark Two.
Slartibartfast explains that the Magratheans are creating this new planet based on their original blueprint. He adds that Earth Mark Two was commissioned to be built by the mice, who were extremely upset about Earth’s destruction because it occurred mere minutes before the Earth could fulfill its intended purpose. Incredulous, Arthur asks Slartibartfast for clarification. Slartibartfast explains that mice are extremely intelligent pandimensional beings who have been running experiments on humans for years. Arthur tries to correct him, explaining that it was actually humans who ran experiments on mice. Smirking, Slartibartfast insists that humans were part of an organic supercomputer designed to run a ten-million-year program. Slartibartfast proceeds to tell Arthur the entire story.
The narrator opens chapter 25 by presenting the many problems with life and describes how the incredibly intelligent pandimensional beings, who have humanoid forms in their own universe, got sick of the constant arguing about the meaning of life, so they created a supercomputer—called Deep Thought—to find the answer. Fook and Lunkwill, two of Deep Thought’s programmers, ask Deep Thought if it can come up with a simple answer to the Ultimate Question of Life, the Universe, and Everything. Deep Thought responds that it can produce these answers when Vroomfondel and Majikthise, representatives from the Amalgamated Union of Philosophers, Sages, Luminaries, and Other Thinking Persons, voice their concerns that if Deep Thought answers such questions, it will make their jobs irrelevant. Deep Thought interrupts Vroomfondel and Majikthise’s tirade and declares that it is now committed to answering the Ultimate Question of life and that this calculation will take seven and a half million years. Deep Thought placates Vroomfondel and Majikthise by pointing out the money they can make as they speculate the answer during that time.
Arthur appreciates Slartibartfast’s story but admits he still doesn’t understand what it has to do with mice and Earth. Slartibartfast points out that the story isn’t complete and invites Arthur to come to his office and watch the results of Deep Thought’s program on his Sens-O-Tape.
Slartibartfast hands Arthur two wires, which give Arthur the sensation that he’s suspended in midair above a beautiful city. Arthur notices a celebration is taking place: People line the streets, and a band plays somewhere in the background. A man standing on a dais addresses the crowd, informing them that the time of waiting is over. He announces that The Day of the Answer, the day they’ve waited seven and a half million years for, has finally arrived. Suddenly, Arthur is spirited away to the room where Deep Though resides. He sees Loonquawl and Phouchg, ancestors of Deep Thought’s original programmers, waiting anxiously for Deep Thought to produce the answer to the Question of Life, the Universe and Everything. Deep Thought suddenly comes to life and informs Loonquawl and Phouchg that it has the answer, but they might not like it. Loonquawl and Phouchg dismiss Deep Thought’s concerns and prompt it to give them the answer. Deep Thought majestically reveals that the answer to Life, the Universe, and Everything is “forty-two.”
Stunned by Deep Thought’s answer, Loonquawl and Phouchg press Deep Thought for more information, only to have it explain that its computations were very thorough. Deep Thought suggests that the problem is that they do not know the Ultimate Question of Life, the Universe, and Everything. Deep Thought explains that if they truly knew the question, the answer would make more sense. Loonquawl and Phouchg ask if Deep Thought can tell them the question, but it responds no, which causes them to sink into despair. Deep Thought then informs Loonquawl and Phouchg that it can build a supercomputer made from organic life that can compute the question and that this new supercomputer will be called Earth. The Sens-O-Tape suddenly ends, and Arthur finds himself back in Slartibartfast’s office.
Back in the depths of Magrathea, Ford and Trillian wake Zaphod. They explain that they had been yelling until someone placed them in a Sens-O-Tape catalogue, which cycles through the various planetary possibilities Magrathea has to offer, producing illusions of different landscapes. Taking in his surroundings, Zaphod begins to recount a story about Yooden Vranx, the Galactic President who served before Zaphod. Zaphod reminds Ford about how they both met Vranx, and Ford recounts the story to Trillian.
Ford explains how a young Zaphod raided a megafreighter that was captained by Vranx, and Vranx was greatly impressed with Zaphod. Zaphod then reveals that Vranx came to see him just before he died and told him about the Heart of Gold. During that visit, Vranx gave him the idea to steal the Heart of Gold, a feat only possible at the launching ceremony. Zaphod explains that he set himself up to become Galactic President for the sole purpose of being at that ceremony so he could steal the Heart of Gold. Zaphod adds that he must have messed around with his own brain so his plan wouldn’t be detectable on the brain-scanning test for Galactic President. At this point, a Magrathean man enters the room and informs the group that the mice are ready to see them.
Back in Slartibartfast’s office, Slartibartfast sums up the totality of the events for Arthur: how Deep Thought designed Earth, how the Magratheans built it, and how five minutes before Earth’s ten-million-year program was complete, the Vogons destroyed it. Arthur suggests that this explains a strange feeling he’s had his entire life that something big and diabolical was occurring, an idea that Slartibartfast dismisses as common paranoia. Slartibartfast then explains that he’s been assigned Africa on the replacement Earth and that he plans to build fjords there despite being told that fjords are not equatorial. A light flashes on the wall, and Slartibartfast tells Arthur that the mice will see him now. Slartibartfast says that there’s a lot of excitement on Magrathea about Arthur’s arrival and that some are saying his being here is the third most improbable event in the history of the universe. As they leave Slartibartfast’s office, Arthur comments that he has been having trouble with his lifestyle.
Trillian, who is eating at a beautifully set table with Ford and Zaphod, greets Arthur and Slartibartfast as they enter the room. Zaphod fills Arthur in regarding their recent interactions with their hosts. Trillian then introduces Arthur to Benjy mouse and Frankie mouse, the two mice from Earth Trillian brought with her onto the Heart of Gold who are also seated at the table.
After Benjy dismisses Slartibartfast, he tells Arthur that he and Frankie are seeking the Ultimate Question, adding that the answer to the universe—forty-two—needs a question they can cash in on. Benjy and Frankie explain that they can’t wait another ten million years to run a new program, and since Arthur was a part of the organic computer Earth, his brain may contain the answer, so Benjy and Frankie offer to buy the answer from him. Arthur sharply declines their offer. Benjy and Frankie coldly tell Arthur that they plan to take the answer anyway, and they lift off from the table in small platforms that hypnotize Arthur. Trillian attempts to drag the motionless Arthur toward the door. Meanwhile, Ford and Zaphod pry open the door and are confronted by a group of Magrathean ruffians. Suddenly, every alarm on the planet sounds.
As alarms go off around Magrathea, Frankie and Benjy mouse lay on the floor, their transport having been destroyed. Arthur has escaped, and Benjy suggests that his and Frankie’s only recourse is to fake the Ultimate Question. Frankie suggests, “How many roads must a man walk down?” Benjy believes that this suggestion may work, and the two share a celebratory dance.
Meanwhile, Arthur, Ford, Zaphod, and Trillian run through the hallways of Magrathea, searching for a way out, when two galactic police officers catch up with them in a large computer room and begin to shoot at them. The officers announce that they don’t want to shoot anyone but continue shooting anyway. After a short exchange, Zaphod and Ford plead for their lives, and the officers reveal several interesting bits of information about themselves, hoping to appear more humane. The officers then threaten to blow up Magrathea if Zaphod doesn’t surrender. As no one will come out, the officers continue to fire at the group, disintegrating the computers Zaphod, Arthur, Ford, and Trillian were using as cover and forcing them to huddle together and wait for the end.
The shooting suddenly stops, and Ford tentatively looks out to see the two officers lying facedown on the floor. Zaphod, Ford, Arthur, and Trillian cautiously advance on the prone officers and, upon examining them, discover that they are from Blagulon Kappa, a methane-breathing planet and therefore had been wearing life-support mechanisms to survive Magrathea’s oxygen-rich atmosphere. Both of the officers’ space suits’ life-support systems mysteriously exploded, and they died. Ford and Zaphod pick up the officers’ guns, and the group runs down the corridor to find Slartibartfast’s empty aircar waiting for them with a note instructing them to push a specific button.
The aircar races to the surface of Magrathea and deposits the group next to the Heart of Gold before zipping back into the planetary tunnels. The group finds the Blagulon Kappa police starship, oddly silent, parked next to the Heart of Gold. Trillian, Zaphod, and Arthur rush to the Heart of Gold, but Ford decides to investigate the police starship and trips over Marvin, who is lying on the ground. Marvin complains that Ford doesn’t really want to talk to him and that everyone, including other robots, hates him. Ford contradicts Marvin, but Marvin explains that even the police starship hated him. He explains that after finding himself alone on Magrathea’s surface, he became bored and depressed and jacked into the police starship’s computer. After explaining his view of the universe to the starship, it committed suicide.
As the crew puts several light-years between itself and Magrathea, each member begins to settle into the starship, including Arthur. Arthur begins to read The Hitchhiker’s Guide to the Galaxy, when Zaphod calls, asking if he’s hungry and informing him that they are going to get a bite to eat at the Restaurant at the End of the Universe.