In 1965 twelve children are gathered together on a deserted moor when they become surrounded by a harsh, bright light, and then suddenly they are gone. Back in the present day, all over planet Earth, children stop moving. Stop playing. Stop laughing. Stop everything. Then, as one, they begin to speak with the same voice, announcing to the governments of the world the imminent arrival of a new alien threat. It becomes clear to the Torchwood team that this isn't the aliens' first visit to Earth, and a terrible price is going to be paid for sins of the past.