He is first made known when he rings Gordon Edgley's home phone. Valkyrie answers the phone after some hesitation and ends up hanging up on the man. He first appears when he attacks Valkyrie while she is in Gordon's house. He grabs her and asks her for the key to the Caves below Gordon's house. Skulduggery then breaks down the door and rescues her. Skulduggery sets hurls a fireball at him, only to find out that he is impervious to fire, leaving the assassin mocking him and asking for more. Skulduggery then responds by shooting him in the shoulder, upon which the man screams in pain before fleeing.
Shortly later he crashes into the Bentley and pulls Valkyrie out of the wreck. He asks her for the key again and she hurts him before running. Valkyrie then jumps into a canal and the assassin, who had just grabbed her shoulder, was dragged in after her. Because he was impervious to fire, water was his weakness. Skulduggery reveals that "the cost of that little spell was that a large amount of water would be lethal. Every big spell has a hidden snag."
He is mentioned in it and his name is revealed as Vindick Leather. It is said that he had been born too late to be of real use to Mevolent's forces, but he believed that Serpine would continue to lead them and one day open the portal to let the Faceless Ones in. It was also mentioned that he only takes showers instead of baths, as total submersion in water is deadly for him.