In this episode, Captain Jack calls in Martha Jones (Freema Aygeman - Doctor Who) to investigate mysterious deaths. When the trail leads to a sinister medical testing centre, Martha must go undercover. However, has Torchwood under-estimated how far the testing centre will go to find medical breakthroughs? How safe are any of the Torchwood team?
Alan Dale (The OC, Ugly Betty, 24, Lost) also guest-stars as Professor Aaron Copley, who runs a sinister medical research centre.