In 1985 the Observer Colour Magazine paired up the naturalist Mark Carwardine and the writer Douglas Adams and invited them to travel to Madagascar in search of the aye-aye, a strange and little known nocturnal lemur thought to be on the edge of extinction.
Douglas and Mark found that they enjoyed the journey, and each other's company, to such a degree that they decided to spend a year travelling the globe in search of other endangered animals.
Douglas said of his contribution to the series: "My role, and one for which I was entirely qualified, was to be an extremely ignorant non-zoologist to whom everything that happened would come as a complete surprise."
According to Mark, "We put a big map of the world on a wall, Douglas stuck a pin in everywhere he fancied going, I stuck a pin in where all the endangered animals were, and we made a journey out of every place that had two pins. "
The journeys took Mark and Douglas to Zaire in search of the Northern White Rhino, to New Zealand in search of the Kakapo, to China in search of the Yangtze River Dolphin, Rodriguez in search of the Megabat, the Amazon in search of the Manatee, Uganda in search of the Gorilla and the Indonesian island of Komodo in search of the Komodo Dragon.
In 1990 the book Last Chance to See by Douglas Adams and Mark Carwardine was published as a companion to the BBC radio series of the same name.
Though Last Chance to See has enjoyed lives as a hardback book, a paperback book, a radio series, an audio book and a CD ROM, attempts to make a television series have so far foundered.
In 2001 Douglas and Mark were discussing the possibility of new adventures, but before plans were made Douglas suffered a heart attack and died.
Stephen Fry was a close friend of Douglas Adams, and when Douglas and Mark spent a year travelling the world, Stephen lived in Douglas' house, and recalls "taking urgent phone calls to send maps and lenses to faraway places."
In 2008-09, exactly 20 years after the original journey, Stephen and Mark head off to see what has become of the animals in two decades, and to discover what has affected their fortunes.