When PC Andy arrests a teenager for shoplifting, he thinks it's going to be a routine case. Then he sees the weapon she's carrying and decides to call in Torchwood. Under questioning from Gwen, the girl remembers her name but little else, and when she speaks it's in a strange mix of English and Scandinavian but with a Cardiff accent. Then the girl's blood tests come through and the team is faced with a dilemma.