A secret cabal of demonic forces threatens to destroy civilization and plunge the world into a new Dark Age. Humanity’s only chance is a shadowy organization called GRAIL–the modern day heirs to the Knights Templar–which has discovered the secret to time travel. The past cannot be changed, but if GRAIL can send an agent into the past to recover a lost book on demonology called the Codex Babylon, they may have a fighting chance to save humanity from utter destruction.