Evelyn is a clever orphan at the Fountainbridge Institute for Destitute Girls. Enchanted by a cheerful lamplighter who fires the streetlamp outside her window each evening, she mesmerizes the other girls with flights of fancy. In a time before Freudian awareness of sexuality and the subconscious mind, such tales are forbidden by the institute's governor, who warns Evelyn to cease her nocturnal storytelling.

Evelyn defies him -- and is cast out of the orphanage and sacrificed to a shadowy figure claiming to be her long-lost father. Who is this man, and why does he lock Evelyn away in a hunting lodge?

Years later, the mutilated body of a professor of ecclesiastical law turns up on one of Edinburgh's finest streets; the grave of a famous colonel is ravaged; a shady entrepreneur is slaughtered while dashing for a train; and a retired lighthouse keeper is ripped to shreds while walking his dog -- all this after Evelyn, now a young woman, has reappeared in the city. What connects the victims? And what of Evelyn, anguished and appealing, who repeatedly claims to have dreamed the murders in great detail -- each time blaming a mysterious "lamplighter"?

Leading the official investigation is Carus Groves, a conceited yet effective police inspector desperate to cap his unremarkable career with a sensational case. Heading up the unofficial investigation is a disillusioned professor of logic and metaphysics, Thomas McKnight, and his assistant, Joseph Canavan, a strapping young gravedigger. Using reason, intuition, philosophy, and luck, these men race to solve the murders and unveil the source of Evelyn's torment, and in so doing penetrate the very gates of Hell.