Edinburgh, 1860s: At the Fountainbridge Institute for Destitute Girls, clever orphan Evelyn Todd spins fantastic tales of the lamplighter who passes her window nightly. Her imaginings, forbidden by the home's strict governor, are all but forgotten when Evelyn is spirited away by a man who claims to be her father. Years later, a wave of vicious killings stains the city's cobbled streets. Three men from different worlds are drawn to the sensational case: a detective hungry for recognition, a disillusioned professor of logic, and a strapping gravedigger. Their paths lead to Evelyn Todd, a woman haunted by dreams of the murders and of a mysterious lamplighter. As her nighttime terrors begin to illuminate the face of the dreadful predator, this unusual trio of investigators uses reason, intuition, philosophy, and luck in a hunt that rapidly hurtles past the bounds of conventional detection.