, Ford Prefect, Trillian, and Zaphod Beeblebrox leave the planet Magrathea on the Heart of Gold. A Vogon ship attacks them, and Arthur's attempt to have the ship's computer make him a cup of tea leaves the Heart of Gold unable to fight it off. Zaphod calls up his ancestor Zaphod Beeblebrox the Fourth to rescue them. Zaphod and Marvin vanish, leaving the others on the ship in a black void. Zaphod and Marvin find themselves on Ursa Minor Beta, the home planet for the offices of the Hitchhiker's Guide. Zaphod goes looking for Zarniwoop, the Guide's lead editor, though his staff insist he has been out on a intergalactic cruise. A man named Roosta takes Zaphod to Zarniwoop's offices just as Frogstar fighters attack the building and tow it to their home planets, Frogstar World B. Following Roosta's instructions and escaping through Zarniwoop's office's windows, he is caught by Gargravarr and taken to be exposed to the Total Perspective Vortex, a device that drives those that experience it mad due to showing them their insignificant contributions to the infinite universe. However, Zaphod is unfazed by the Vortex, telling a perplexed Gargravarr that it showed him that he was the most important being in the universe. Left to his own, Zaphod eventually finds Zarniwoop on a long-abandoned spaceliner. Zarniwoop reveals that once Zaphod stepped into his offices, he has been in a virtual universe designed for Zaphod's benefit for purposes of bringing the Heart of Gold, which had been microscopically shrunk and in Zaphod's pocket, to Zarniwoop, so that Zarniwoop can use it to find the true ruler of the universe. However, Zaphod reunites with Ford, Arthur, and Trillian, and escape to the nearest restaurant. This turns out to be the Restaurant at the End of the Universe, built atop the ruins of Frogstar World B and existing in a time bubble near the end of the universe; they also find Marvin, now billions of years old, having been waiting for them as a parking attendant. Knowing Zarniwoop will track them down, Zaphod suggests they leave, stealing a sleek, all-black spacecraft. Too late they discover this is a special stunt ship for the band Disaster Area, which is programmed to fall into a local sun in time with the band's climax. Marvin reluctantly volunteers to stay behind and operate a teleporter so the others can escape. Zaphod and Trillian find themselves back aboard the Heart of Gold under Zarniwoop's control, and who forces them to use the ship's Improbability Drive to take them to The Ruler of the Universe. On a unpopulated planet, they find the Ruler is an old man that has no idea he is the ruler, and is even skeptical if anything around him exists. While Zarniwoop tries to reason with the Ruler, Zaphod and Trillian make their escape in the Heart of Gold, stranding Zarniwoop. Meanwhile, Arthur and Ford find themselves aboard the Golgafrinchan Ark Fleet Ship B, which they discover was a way for the Golgafrinchans to divest themselves of a useless portion of their population by claiming a planetary disaster is coming. The Ark crashes onto a planet, which Arthur and Ford determine is pre-historic Earth, and they fear that the Golgafrinchans, who have been killing the Neanderthals, will interfere with the machinations of the computer Deep Thought had built to determine the Ultimate Question to Life, the Universe and Everything, which the Answer is 42. Hoping that remnants of prehistoric humans are still under the programming, they use a make-shift Scrabble set and have Arthur pull out tiles at random, discovering that the Question is "What do you get if you multiply six by nine?" Ford thinks this explains why the universe is a giant "cock-up", and the two resign to make the best of their life on prehistoric Earth.
Audiobook adaptations
There have been three audiobook recordings of the novel. The first was an abridged edition, recorded in 1981 by Stephen Moore, best known for playing the voice of Marvin the Paranoid Android in the radio series, LP adaptations, and in the TV series. In 1990, Adams himself recorded an unabridged edition, later re-released by New Millennium Audio in the United States and available from BBC Audiobooks in the United Kingdom. In 2006, actor Martin Freeman, who had played Arthur Dent in the 2005 movie, recorded a new unabridged edition of the audiobook.
Reception
reviewed The Restaurant at the End of the Universe in Ares Magazine #13 and commented that "The Restaurant at the End of the Universe tries to do much of the same thing, but some of the zest seems to be missing; the ideas are fewer, the happenings less dramatic. The author seems sometimes to be straining for the same effects he effortlessly achieved in Hitchhiker."