Someone - or something - is killing the vampires of London while they sleep during the day. Don Simon Ysidro, the oldest of the London vampires, hires Dr. James Asher, a retired member of the British Secret Service, to find this killer. Asher, who accepts this job for the price of his wife (Lydia)'s life, delves into the shadowy world of the vampires to find a killer that increasingly seems to be one of their number.

"My name is Don Simon Xavier Christian Morado de la Cadena-Ysidro, and I am what you call a vampire."
-Ysidro