The various versions follow the same basic plot but they are in many places mutually contradictory, as Adams rewrote the story substantially for each new adaptation.[12] Throughout all versions, the series follows the adventures of Arthur Dent, a hapless Englishman, following the destruction of the Earth by the Vogons (a race of unpleasant and bureaucratic aliens) to make way for a hyperspace bypass. Dent's adventures intersect with several other characters: Ford Prefect (an alien and researcher for the eponymous guidebook who rescues Dent from Earth's destruction), Zaphod Beeblebrox (Ford's eccentric semi-cousin and the Galactic President who has stolen the Heart of Gold, a spacecraft equipped with Infinite Improbability Drive), the depressed robot Marvin the Paranoid Android, and Trillian (formerly known as Tricia McMillan) who is a woman Arthur once met at a party in Islington and who—thanks to Beeblebrox's intervention—is the only other human survivor of Earth's destruction.
In their travels, Arthur comes to learn that the Earth was actually a giant supercomputer, created by another supercomputer, Deep Thought. Deep Thought had been built by its creators to give the answer to the "Ultimate Question of Life, the Universe, and Everything", which, after eons of calculations, was given simply as "42". Deep Thought was then instructed to design the Earth supercomputer to determine what the Question actually is. The Earth was subsequently destroyed by the Vogons moments before its calculations were completed, and Arthur becomes the target of the descendants of the Deep Thought creators, believing his mind must hold the Question. With his friends' help, Arthur escapes and they decide to have lunch at The Restaurant at the End of the Universe, before embarking on further adventures.
