During a shootout with the police, a suspect in the kidnapping and possible murder of a blackjack dealer and her husband takes his own life. Searching his ranch, the CSIs find the kidnapping victim's head mounted onto a plaque, but no sign of her husband. As the investigation continues, it is revealed that the dead suspect and several others connected to him belonged to a strange cult in which it is believed that certain people are secretly intelligent reptilian creatures set on conquering mankind.