England, 1882. In Victorian London, two children with mysterious powers are hunted by a figure of darkness —a man made of smoke. Sixteen-year-old Charlie Ovid, despite a lifetime of brutality, doesn't have a scar on him. His body heals itself, whether he wants it to or not. Marlowe, a foundling from a railway freight car, shines with a strange bluish light. He can melt or mend flesh. When two grizzled detectives are recruited to escort them north to safety, they are forced to confront the nature of difference, and belonging, and the shadowy edges of the monstrous.