The Rhesus Chart (2014) is the fifth novel by Charles Stross in his "Laundry" series of Lovecraftian spy thrillers. The previous novels in the series were The Atrocity Archives (2004), The Jennifer Morgue (2006), The Fuller Memorandum (2010), and The Apocalypse Codex (2012). The novels follow the protagonist Bob Howard, an agent for the intelligence agency known as the Laundry.
The Rhesus Chart plot describes the discovery and resolution of several Vampire threats, when everyone had known previously that there was no such thing as vampires. Howard's personal and professional lives cross and cross again.
It received a Kirkus Reviews starred review.