This page refers to the original book, first published in 1979. For overall concept, see Hitchhikers Guide to the Galaxy
1.1 Arthur’s house is about to be demolished; meanwhile Earth is also about to be destroyed by Vogons. 1.2 Ford reveals he’s an alien researcher for the Guide and pulls Arthur to the pub before rescue. 1.3 The Vogon fleet appears; Earth is destroyed.Arthur and Ford hitch a ride on a Vogon ship. 1.4 Ford explains the Guide; Arthur tries to understand the scale of the universe. 1.5 Vogons discover the hitchhikers and subject them to poetry torture.
1.6 Arthur and Ford are ejected into space; improbably rescued by the Heart of Gold. 1.7 Zaphod, Trillian, and Marvin are introduced aboard the Heart of Gold. 1.8 Zaphod insists on visiting Magrathea despite warnings it’s dead. 1.9 The ship receives a threatening message from Magrathea; Zaphod decides to land anyway. 1.10 The group prepares for landing; Magrathea fires missiles. 1.11 The Infinite Improbability Drive saves them by transforming the missile into a whale and a bowl of petunias. 1.12 Zaphod sends Arthur, Ford, and Trillian to explore the surface while he and Marvin stay behind. 1.13 Arthur meets the elderly Magrathean Slartibartfast. 1.14 Slartibartfast reveals Magrathea’s planet-building business and invites Arthur to see more. 1.15 They enter the Magrathean archives; Arthur learns Earth was a supercomputer built to find the Answer. 1.16 Zaphod, Trillian, and Ford are captured by Magratheans but recognised as harmless. 1.17 History of the creation of Deep Thought, the computer built to find the Answer. 1.18 Deep Thought reveals that the Answer is “42,” but no one knows the actual Question. 1.19 A new computer — Earth — is designed to compute the Question itself. 1.20 Earth’s ten-million-year program is described; five minutes before completion the planet was destroyed. 1.21 The mice reveal themselves as pan-dimensional beings; they want Arthur’s brain to extract the Question. 1.22 The mice chase Arthur; the group escapes with the help of a robot riot staged by Zaphod. 1.23 The group flees Magrathea under heavy attack. 1.24 Safe aboard the Heart of Gold, they reflect on Earth’s destruction and the absurdity of their situation. 1.25 Arthur tries to have tea; fails repeatedly due to ship machinery and Improbability quirks. 1.26 Trillian’s backstory: how Zaphod picked her up from Earth after meeting her at a party. 1.27 Zaphod’s backstory: he deliberately wiped parts of his own brain to hide his real motives. 1.28 Ford and Zaphod talk; Zaphod admits he doesn’t know what he was trying to find. 1.29 The group watches the news and realises they are now highly wanted criminals. 1.30 Zaphod decides they need a proper meal and sets a course for the Restaurant at the End of the Universe. 1.31 Arthur continues struggling with tea; Marvin continues being crushingly depressed. 1.32 A philosophical argument erupts with synthetic personalities of ship components. 1.33 Ford explains the dangers and weirdness of the End of the Universe. 1.34 The ship approaches the Restaurant; the crew prepare mentally for seeing the universe end repeatedly. 1.35 The novel closes with the crew heading to the Restaurant at the End of the Universe, setting up the next book.