Blackthorn key

As the plague decimates London in 1665 and an assassin threatens the apothecary's life, apprentice Christopher Rowe and his faithful friend Tom, following a trail of puzzles, riddles, and secrets, risk their lives to untangle the heart of a dark conspiracy.

Christopher Rowe has no idea who he is. After being shipwrecked in Devonshire, he wakes up alone, his memories gone. Villagers tell him he was possessed by an unseen evil, and only became conscious after being visited by the local witch. As Christopher tries to get his bearings, he realizes his current state may be far from coincidence. Dark events have been happening in this corner of Britain—village children are disappearing without a trace....

Christopher, Tom, and Sally engage in a dangerous cat and mouse game with the Raven as Christopher attempts to finally unmask him.