When the Doctor and Rose return to Cardiff in 1869, they discover corpses that have been alive by an enigmatic blue vapor in a funeral parlor owned by Gabriel Sneed and his clairvoyant servant girl, Gwyneth. The Doctor and Charles Dickens work together to find Rose after she is abducted by Sneed and Gwyneth. The gang is reunited in the funeral parlor, where the Doctor concludes that the blue mist is caused by a being attempting to bridge a rift in the spacetime upon which the parlour is constructed. They are identified as the Gelth, who use Gwyneth as a bridge and animate bodies until they can construct their own. The Gelth lie about their numbers and intentions, intending to kill billions of living humans, and not just inhabit existing corpses. Gwyneth volunteers to ignite the gas which Dickens flooded the cellar with, closing the rift and trapping all the Gelth. The Doctor, Rose, and Dickens escape before the parlour is engulfed in flames.