Fleeing across a roof on a dark night in Victorian London, a thief crashes through a skylight to almost certain death. But a young doctor reconstructs his shattered body, and unwittingly provides him with the key to a new existence. On his release from prison he begins to lead a double life, becoming both the respectable, wealthy Montmorency and his degenerate servant, Scarper. Meanwhile, the police are baffled by a wave of mysterious thefts… But Montmorency must be on his guard at every moment. The smallest mistake could reveal his secret and destroy both his lives.