Christopher Samuel Youd (1922 – 2012) was an English author best known for his science fiction published under the name of John Christopher.
Several of his novels have been filmed. The Tripods was adapted for television, although the series was cancelled before getting to the last book.
- The Death of Grass
- The Tripods series
- the Sword of the Spirits trilogy (The Prince In Waiting, Beyond the Burning Lands, The Sword of the Spirits)
- Dom and Va
- A Dusk of Demons
- Attack Its Weak Point: In Beyond the Burning Land, Luke fights and kills the Bayemot (a giant ameoba-like creature) by striking at its nucleus deep inside its body with a sword.
- Cozy Catastrophe: The Death of Grass (disease wipes out all grasses, including those that are staple foods for humans), The World in Winter (an ice age) and A Wrinkle in the Skin (earthquakes).
- Feudal Future: The Sword of the Spirits series is set mostly in England, centuries after a nuclear-war-like natural disaster. England is a bunch of warring city states ruled by princes, but with a dominant anti-technology religion in which people worship Spirits.
- Ghost City: London in Empty World.
- Lightning Can Do Anything: In Fireball two cousins are transported to ancient Rome (later revealed to be an alternate reality) by what they assume to be some form of ball lightning.
- Market-Based Title: Several of his novels were given different titles in the United States. No Blade of Grass, the US title of The Death of Grass, went on to be used as the title of the film adaptation.
- Mayor of a Ghost Town: The protagonist of the post-pandemic London of Empty World.
- Nasty Party: In The Prince in Waiting, the protagonist's father (ruler of the city where the action is set) is invited to a gathering and murdered.
- One Nation Under Copyright: The Year of the Comet
- Possessive Paradise: The Lotus Caves
- Saharan Shipwreck: In A Wrinkle in the Skin, massive earthquakes redistribute the balance of ocean and land, and the protagonist comes across a large tanker sitting in the desert which used to be the seabed.