The Watcher in the Shadows (Carlos Zafón, 2014)

A mysterious toymaker who lives as a recluse in an old mansion, surrounded by the mechanical beings he has created... an enigma surrounding strange lights that shine through the mists that envelop the small island on which the old lighthouse stands... a shadowy creature that hides deep in the woods... these are the elements of a mystery that bind 14-year-old Irene to Ismael during one magical summer spent in the Blue Bay. Irene's mother has taken a job as a housekeeper for the toymaker, Lazarus, but his house contains more secrets than Irene and Ishmael have bargained for.