An ordinary day becomes a world of terror, as every single child in the world stops. A message is sent to all the governments of Earth: "We are coming." But as a trap closes around Captain Jack, sins of the past are returning, as long-forgotten events from 1965 threaten to reveal an awful truth.

Torchwood is forced underground, as the government takes swift an brutal action. With members of the team being hunted down, Britain risks becoming a rogue state, with the mysterious and powerful 456 drawing ever closer. Captain Jack, Gwen and Ianto are helpless, as events escalate until mankind faces the end of civilization itself.