When a teenage girl is found almost beaten to death, Don and his team discover that she escaped from a polygamous cult headed by a fundamentalist leader who is on the run from the FBI. They discover that the girl's mother, who is also a religious zealot, "gave" her daughter to the leader. As their contribution to the investigation, Charlie and Amita try to decipher a chart that was found at the leader's last known location, hoping it will lead them to him. Millie provides them with a surprising answer.

When Charlie and Amita return prematurely from a math conference to work the investigation, they find Alan and Millie sharing a bottle of wine in the Eppes homestead.