The Rhesus Chart

Discover a supernatural thriller about an intelligence agent working for 'the Laundry', a top secret government agency that deals with occult powers threatening the realm. Although they've handled many threats, they've never come across vampires until a team of investment bankers develops an arcane algorithm that turns them into blood-craving creatures. Join Bob Howard in his fight against the literal bloodsuckers running London's financial district in The Rhesus Chart by Charles Stross.