The bats aren't the only things to leave the ship that foggy, London night in 1850. A small, frightened figure scurries down the gangplank and staggers on to the docks. Ben has been on board for the whole voyage and what he has seen will haunt him for the rest of his life.

Jack befriends him and listens to his story. It's a wild, outlandish tale of archaeology, superstition and a strange fatal sickness. As the two boys talk, little do they know what thet face. London is falling into the terrifying grip of the vampire plagues and only they can prevent its total destruction...