The Hitchhiker's Guide to the Galaxy

There is no definitive version. Douglas Adams rewrote the story completely for every medium it entered, and the radio series, the novels, the television programme and the film contradict each other on plot, on characters and on who survives. He considered that correct.

1978: a radio comedy on BBC Radio 4

The first episode was broadcast in March 1978, late at night, on a network with no audience for science fiction. Adams was 25 and had written for Doctor Who.

He gave the origin as lying drunk in a field in Innsbruck in 1971 with a copy of a hitchhiking guide to Europe. The idea sat unused for years.

The radio format shaped everything that followed. The Guide itself is a voice reading entries aloud, which works because a listener has no screen, and every later version had to find a way to keep it.

Six media, six incompatible plots

The novel appeared in 1979 and sold 250 000 copies in three months. A television series followed in 1981, a computer game in 1984, a film in 2005, and further radio series adapting the later books in 2004.

The books have sold more than 15 million copies. Each version changes the story. Characters die in one and not in another; the Earth is destroyed differently; the ending of the radio series has no equivalent in print.

Adams described the result as a trilogy in five parts, which was a joke about his own inability to stop, and which is now a standard formula for any series that outgrows its plan.

An author who could not finish anything on time

Adams missed deadlines so consistently that it became part of his public identity. He said he loved deadlines and the sound they made as they went past.

His publisher locked him in a hotel suite for three weeks to extract one novel, sitting with him to make sure he wrote. He produced eleven books in twenty-three years, which for a writer of his sales is very few.

He died in 2001 at 49, having spent two decades trying to get the film made. It reached cinemas four years after his death, using a script he had worked on.

The jokes that turned into products

The Guide is a handheld electronic device holding the collected knowledge of the galaxy, written by contributors, frequently wrong. Adams described it in 1978.

The Babel fish translates any language in the ear of the listener, and the name has been attached to translation services since the 1990s. The number 42 is a joke with no meaning that has been searched for meaning for forty-five years.

Adams spent his last years arguing that the internet would change how people think. He is one of very few comic writers whose throwaway inventions became consumer categories.