The CBI are investigating the murder of lawyer Gordon Hodge, who only had one client, the Sinner Saints. Lisbon, Rigsby and Jane question the wife and son but don't get much information about his clients.
They go to the lion's den and question the leader of the Sinner Saints, Von McBride, and figure out that Hodge was doing drugs. They think he could have been an informant for the Sinner Saints. McBride doesn't seem to care, even when a woman comes to the bar and calls him a murderer.
They track her down. Her name is Felicia Gutherie and she believes that McBride killed her brother. Hodge had gotten him out of the charges in court. She had been stalking Hodge and they move her to the number one suspect but she denies killing him.
Van Pelt also discovers that Hodge was having multiple cell phone conversations with McBride's girlfriend, Diamond. Turns out that Hodge was having an affair with Diamond. Diamonds flees Lisbon because she doesn't want McBride to find out. She says the only other person who knew was Mrs. Hodge.
Lisbon talks to his wife who admits that she knew but she didn't want their son Lucas to find out. Lisbon takes Lucas for a ride and finds that he had talked to Felicia one time when she stopped by but didn't have anything to say about the conversation.
Cho and Rigsby decide to stake out at Felicia's house just in case she disposes of any evidence. The Sinner Saints show up to try and get revenge on the supposed killer, but Cho and Rigsby threaten them to get them to leave.
Jane and Lisbon join Cho and Rigsby at Felicia's house to search for evidence. They find one of Hodge's missing cuff links in her trash can and arrest her. Mrs. Hodge and Lucas are down at the station. Mrs. Hodge urges Lucas to leave but he stays.
Lucas ends up confessing to killing his father after getting angry that his father was having another affair. His mother had helped him cover up the murder. Jane had planted the cuff link in the trash to make Felicia look guilty so that Lucas would fess up to the crime.
Jane meets with McBride outside the bar. Jane hands him an envelope with the identity of the informant inside. Jane disappears and the gang discovers that the envelope had money inside, making it seem that McBride is the informant. They take McBride out to exact his punishment and we see Felicia watching the whole scene from the dumpster nearby.