Steampunk is a retrofuturistic subgenre of science fiction that incorporates technology and aesthetic designs inspired by 19th-century industrial steam-powered machinery. Although its literary origins are sometimes associated with the cyberpunk genre, steampunk works are often set in an alternative history of the Victorian era or the American "Wild West", where steam power remains in mainstream use, or in a fantasy world that similarly employs steam power. When a bizarre string of locked-room murders terrorize New York, the police have no leads, no suspects, and only one place to turn. Now private detective Alex Lockerby will need every magic trick in his book to catch a killer who can walk through walls and leaves no trace.