CSI: Crime Scene Investigation: Season 4, Episode 19

4 - 19:

When a teenage girl is killed in a house fire, Catherine, Nick and Warrick suspect a serial arsonist. Among their suspects are the girl's demented grandmother, a female pyromaniac and the high school baseball team. Meanwhile Grissom and Sara investigate the death of a champion in a popular word game, who is found dead in the men's room with several game tiles in his throat and stomach.