When a man at a party (which both Ryan and Cardoza are working undercover at) falls in a pool of deadly jellyfish, Cardoza risks his life by trying to get the man out of the pool. But when he can’t and the man dies, the CSI’s have a new case to investigate. However, confusions begin when the suspects have different stories on what happened and what caused it. Meanwhile, Delko and Calleigh deal with the victim’s wife, who desperately needs the insurance money. But when they call the insurance company, their investigation takes a small turn.