There is a fire in a house and Catherine, Nick, Warrick arrive at the scene. An arson investigator tells them that there was a fire in the block ten days ago, maybe caused by a serial arsonist. The Abernathy family is rescued, but the daughter Sabrina that was not supposed to be at home is found dead. They begin their investigation looking for the origin of the fire and for suspects. Meanwhile, Grissom, Sara and Capt. Brass investigate the death of a man found dead in a hotel bathroom. In the autopsy, Dr. Robins finds a round tile with the letter in his throat, and five more tiles in his stomach. Brass identifies the victim and Adam Brenner from Florida that was in Las Vegas to participate in a logo game tournament. Soon Grissom learns that Adam was a top player and Grissom looks for opponents defeated by Adams that might be angry.

Dr. Langston confronts Nate Haskell one more time during his murder trial. Meanwhile, Nick faces an old teenage nemesis, Jason McCann, who is seeking revenge for his brother's death.

A killer is about to go free because of a dirty cop, so the team tries to connect him to an earlier crime to keep him in jail.