The team's investigation of a sunken wreck, the Black Mantis, brings them afoul of an insurance inspector who believes they are smuggling stolen artifacts. Seeking to clear their names, the investigation takes them after a ring owned by a Baron Wainright. The Baron has a horde of curiously-undamaged treasures from the ship, purportedly stolen by John Roach, aka Captain John Blood. The Baron's nephew claims that "Baron Wainwright" is actually Roach and they are both vampires.