The movie features a large dragon illustration behind the opening and closing credits. Monty Montague disappears after diving into a natural pool of water on an estate. Several people dive in, but there is no trace of him. Philo Vance and the District Attorney come to investigate and decide to drain the pool. They are told that there are potholes near the pool, and Montague's body is found at the bottom of a very deep pothole. His body has claw marks on it, consistent with the superstition that a dragon inhabits the pool.