Arriving on the back of a meteorite, an alien pathogen has spread rapidly around the world, infecting all living humans and animals, and killing off all insect life. Only plant life seem to be resistant. The infected do not die, however, but instead begin to mutate into horrendous creatures, gaining plant-like qualities and even melding with one another to create monstrosities of nightmare proportions.

Only a handful are immune, and these survivors cling desperately to life, searching for food, fresh water, and a means of escape, find rescue, and discover a way to rebuild.

Becky is a young woman, taking refuge in her flat in the southern English city of Brighton, along with her friend Abby, an Australian woman she met online.

Harry is a member of the Posse, a group of five men enjoying the anarchy of the United Kingdom, smashing and grabbing what they can to survive, caring little for whom they harm along the way.

Brad and his dog Sam are searching Oxford for Brad's fiance, Anne, battling their way to Christ Church College.

Paths will cross, more lives will be lost and destroyed, and the world will give way to its new host.