Samuel Youd - better-known by his pen-name, John Christopher - passed away on Friday at the age of 89.
Christopher is best-known for his adult SF disaster novel, The Death of Grass (1956), and for his YA SF series, The Tripods (1967-68, 1988). The Tripods depicted the aftermath of an alien invasion of Earth, in which humans are forced to wear mind-controlling 'caps' by the three-legged titular aliens (who ride around in HG Wells-esque war machines). The BBC adapted the first two books into a TV series in 1984-85, and rumours of a film version of the trilogy have abounded for years.
Youd also wrote detective and mainstream fiction under a variety of pseudonyms, including Hilary Ford, William Godfrey, Peter Graaf, Stanley Winchester, Peter Nichols and Anthony Rye.