A serial killer is loose in Yorkshire, and has claimed three victims in three months. Thirteen days before each murder, a large purple V is painted on the front door of the victim's house. The victims, all of whom have some association with the occult, are found drained of blood with two red marks on their neck.

When RUBY BARNETT comes home one evening to find a large purple V on her front door, it becomes clear she is the so-called Vampire Killer's next victim. Private Investigators KITT HARTLEY and GRACE EDWARDS have just thirteen days to solve the mystery and save Ruby's life. The clock is ticking . . .