It is London, 1894. Amid the fog, cold and degradation, a gruesome business is being conducted. The bodies of the dead are being stolen from their graves — men, women and children alike — for the sinister purpose of a very mysterious gentleman. When the Eighth Doctor and Sam arrive, they are witness to a horrifying scene in the evil-smelling fog: something rises up from the filthy waters of the Thames and devours a man — a man terrified for his life and on the run from the devil himself...