Thorne is convinced he saw a man pushed off a building roof, but cannot locate the body at first. When the body turns up, Steve and Tessa not only have to track down the killer, but discover why the body disappeared.
Tessa and Steve respond to a murder call only to find no body, no crime scene and they, they suppose, no murder; until they discover that the eye witness is their boss, Inspector Malcolm Thorne. Thorne is convinced he witnessed a man being pushed off the roof of a building, but he is perplexed as the rest of them when no evidence of a crime can be found.