Warrick, Catherine, and Nick try to determine the cause of a house fire that kills a teenage girl. The fire is in the same neighborhood as a similar arson fire. Grissom and Sara investigate a man found dead with letter tiles in his stomach. The man was a competitor in a word game tournament.

A roller coaster runs off its track, leaving six people dead. The CSI team investigates whether this was an accident or foul play. One of the deaths, however, is not what it seems, and this takes the case in an unexpected direction. Meanwhile, Catherine and Warrick investigate the death of a 13-year old girl whose body was dumped unceremoniously outside town.