It starts with a series of unexplained events. Earth tremors across the globe. Women being driven insane by their scrambled senses. Governments and scientists are bewildered and silent. The world needs Torchwood, but there's not much of Torchwood left.

Captain Jack Harkness has tracked the problem to its source: a village in Peru, where he's uncovered evidence of alien involvement. In Cardiff, Gwen Cooper has discovered something alien and somehow connected to Jack. If the world is to be restored, she has to warn him – but she's quickly becoming a victim of the madness, too...