When Jake Crowley rescues Rose Black from assailants on the streets of London, the two find themselves embroiled in a mystery that could cost them their lives. People are dying, and all the victims have one thing in common with Rose: a birthmark in the shape of an eagle.
From beneath the streets of London, to castle dungeons, to the heart of Christendom and beyond, Jake and Rose must race to stay alive as they seek to unlock the secrets of the Blood Codex.