The Restaurant at the End of the Universe by Douglas Adams

Milliways, the Restaurant at the End of the Universe, is the nearest restaurant in space but not time. They escape from Zarniwoop by asking to be transported to the nearest restaurant. It is reconstituted, and Zaphod is reunited with Trillian, Arthur and Ford.

It turns out that Zaphod had the shrunk Heart of Gold in his jacket pocket the whole time. Zarniwoop explains that the Total Perspective Vortex has not malfunctioned - this is a virtual universe created by Zarniwoop for the sole benefit of Zaphod, who is the most important creature in this universe. Zaphod escapes, and finds Zarniwoop in the first class cabin of a space liner that keeps its passengers in stasis as they wait for a re-fill of lemon soaked napkins in an abandoned spaceport. However, when Zaphod enters it, the Vortex shows him that he is the most important thing in the Universe. Zaphod then meets Gargravarr who informs Zaphod that he is to be sent through the Total Perspective Vortex, a torture device which annihilates you by showing you just how infinitely small you are compared to the Universe. Roosta gives Zaphod final instructions before he leaves: Go through the window on his way out, not the door. A mysterious man named Roosta brings Zaphod to Zarniwoop's office, where they wait until the building lands on Frogstar World B.

When Zaphod and Marvin reach the fifteenth floor of the Guide's office, half of the building is lifted off the ground by Frogstar Fighters. Arthur, Trillian and Ford are unaware of any of this, knowing only that the computer has been shut down, and only having received a message from a stalling Nutri-Matic Drink Synthesizer that says 'Wait.' They are looking for Zarniwoop, who has gone on an intergalactic cruise in his office via his virtual universe. Zaphod and Marvin vanish, and reappear at the offices of The Hitchhiker's Guide to the Galaxy editorial building on Ursa Minor Beta. Luckily, an ancestor of Zaphod's, Zaphod Beeblebrox IV, saves them. They find they are unable to use the Improbability drive to escape, as Arthur has accidentally jammed the computer with a simple request for a cup of tea which proved a rather difficult problem. Arthur Dent, Ford Prefect, Trillian, Zaphod Beeblebrox and Marvin have just left the planet Magrathea when they are attacked by a Vogon ship commanded by Prostetnic Vogon Jeltz. The Restaurant at the End of the Universe begins just as The Hitchhiker's Guide to the Galaxy ended.

The Restaurant at the End of the Universe by Douglas Adams