Dr. Sebastian Sallow, a well-respected scientist, and his mysterious and malevolent alter ego. Sebastian experiments with a potion lead to the physical and moral transformation into his alter ego, an embodiment of his darker impulses. Since the incident, strange deaths and murders have begun to appear all over London and no one knows who is responsible, but Sebastian's afraid he has some part to play, which is where you come along, a young detective, eager to prove herself and find the culprit.