Gwen’s first day on her new job at Torchwood sees Cardiff’s night-life at the mercy of a gaseous alien who consumes its victims during orgasm, leaving behind only dust. And it’s all her fault — she let it escape a fallen meteorite. The gas is devouring its teenage host. She’s fighting for control as the alien inside takes down victim after victim. Torchwood tracks the alien to a sperm bank, but too late for the patrons within. Soon, if they don’t act quickly enough, it’ll be too late for everyone else too!