Jane has been spending a lot of nights in the attic above CBI headquarters. Someone calls him asking him for a favor, and Jane drops everything to go and help. When the police are called in to a crime scene, they find Jane holding a gun and standing over the victim's body.
The victim is a prominent businessman named Lester Wale, who was apparently the mark of an elaborate con to part him from his money. The mastermind of the con is a man named Danny Raskin. Jane tells Lisbon that he's not acquainted with Lester and that he personally knows Raskin. Danny is Jane's brother-in-law, and he was the one who called Jane in for a favor.
While trying to track Danny down, Jane realizes the fair is in town, so he goes to check the place out. He falls back into his old crowd of carnival folk and con men and finds Danny, who claims that he didn't kill Lester either. Of course, Danny blames Jane for his sister's death, but then again, Jane does as well.
Lisbon finds Jane and Danny and brings them both in for questioning. Meanwhile Rigsby and Cho are speaking with Lester's wife and his secretary, and it's starting to become clear that he was having an affair behind his wife's back. To coax a confession out of the wife, Danny and Jane go into an elaborate con where Danny pretends to shoot Jane. The wife convinced herself that Lester was having an affair after their expensive statue went missing. She assumed he gave it to his mistress, but in actuality Lester put the statue up as collateral in the con. She confronted Lester to take the statue back and ended up killing him. She's arrested, and Danny was about to be as well (for fraud), but Lisbon lets him go before that can happen. We then find Danny and Jane at a cemetery standing over Jane's family's headstones, and see that their names were Angela Raskin Jane and Charlotte Anne Jane. Danny and Jane make amends and Danny leave Jane with the words, "Guilt is for Marks."