The episode begins with Curtis killing a man in Atlantic City before winning at a slots machine; it is shown that for him, killing and winning go hand in hand. Meanwhile, Garcia drank a lot of wine after a fight with Kevin. She's surprised to find him at her door—and Morgan in her shower. The victim is Danny; part of a crime family, and his body was surrounded by cards, indicating to some sort of a ritual by the killer. "At the gambling table, there are no fathers and sons." Meanwhile, Eddie joins Curtis, on a winning streak. It turns out Danny and Curtis did some business together in the past. Curtis was recently fired for punching his boss in a fit of anger, and he's been on a winning streak since, with his luck on the up and up. A woman takes interest in his winning, which is shown to visibly apparent; Curtis is shown to like the attention.
While Reid and Prentiss note that it doesn't look like this was a premeditated murder at the crime scene, they find out Danny had personal, not security, cameras in his office, which is why they don't have any footage of the murder, and thus they can’t hope to acquire any clues from that quarter. Meanwhile, Curtis' wife Teri shows up to talk to him, she is there for a purpose. He tells her about a poker tournament where he can win a million, and he sounds confident about winning it. She wants a divorce; and doesn’t care much for what he has to say. He doesn't take too well to this news, a fact that is quite apparent. The news in fact comes as shock to him, and he is visibly angered by it. Meanwhile, Morgan and Hotch buy some time with the mob bosses, so they can arrange for the money to settle their dues.
Rossi and JJ found out that Danny loaned money to casino patrons, and it was a part of his business dealings. They're looking for a gambler. Curtis notices the same woman who was hanging off him hanging off another guy; a fact he is visibly not happy about. He follows her to her car, to talk to the woman. When she brushes him off; he feels not only angered but insulted, she thus becomes his next victim. The MO is the same (this time with cash, not cards). Patty was an escort, and they wonder if she was hanging off the big winners. Eddie tells Curtis Teri was holding him back and shows him a photo of the watch he plans to buy when he wins big, he is that confident of winning. When he gives Curtis a dollar to play, Curtis hits four aces, much to his pleasant surprise.
His winning streak is back, and he has noted the pattern, thus he shall probably be make huge amounts of money. The Criminal Minds team gives the profile to the police, so they can be of assistance. Gamblers are extremely superstitious when they are playing, and the unsub is focusing on the number eight. Why? They wonder if he's taken notice of a pattern between killing and winning. Curtis is escalating, as he buys a gun. However, the system has stopped working as he keeps losing, much to his dismay. Meanwhile, Curtis gives Eddie a watch before killing him. The BAU notes evidence of remorse at this crime scene, and Reid mentions that eight signifies prosperity, and thus the number was chosen by the gambler. A second victim was found dead, with $50,000 stolen. They find out about the tournament for that evening—with a $50,000 buy-in.
Hotch is having problems getting the funds, but the team convinces Rossi to stake them the buy-in—and to let Reid, who has figured out a mathematical equation for playing, to go in, as he might be the best bet in pretending to be a gambler. Meanwhile, Prentiss takes photos of all the tournament players, but none fit the profile, that they are looking for. Reid notices Curtis' 8-ball and switches to his table, so he can keep a closer watch. He re-raises on him, and Curtis is obviously rattled when he loses, a fact that becomes apparent like it has with Curtis; many times before. When Reid reaches for the 8-ball, Curtis reacts violently and says Reid was reaching for his chips, he is clearly frustrated and extremely flustered by his loss. Security leads him out, as he is clearly out of line and is disrupting the peace, but Reid signals the team to let go of him, as he being prevented from playing would completely foil their plans.
Curtis notices and runs, as he clearly figures out the fact that he is being kept a watch on. The BAU takes chase, but he's long gone, much to their dismay. The BAU haven’t managed to keep it as discreet as they would have liked, thanks to the security interfering. Meanwhile, they discover that Eddie and Curtis were business partners, and Curtis' father was a compulsive gambler, a trait that has passed on to Curtis. He abandoned his family and drank himself to death, without a care in the world about his responsibilities. Rossi realizes that the closer the relationship he had with the victim, the better Curtis' luck, something that Curtis probably knows very well himself. He's going after his wife, who's at her sister's. Teri tells Liz to call the police, but Curtis has his gun and he's not letting them go anywhere, with the both of them totally helpless.
He can tell she's lying about wanting a fresh start when she tries to talk him down, it’s just a way of her trying to escape with her life. Meanwhile, Rossi enters without his vest and unarmed and identifies himself as JJ tries to get an angle on Curtis, who takes Teri as his hostage; he doesn’t want the women to get hurt and thus enters unarmed. Rossi does convince him to let Liz go and tells him his father's the reason, not Teri, and hence he should let the women go; as they aren’t to be blamed for anything. Curtis is obviously waiting for something, which becomes visibly apparent. They realize he's waiting for 8 o'clock.
Hotch, Prentiss, and JJ move in, and Curtis does let Teri go—but as the clock strikes 8, he says, "The house always wins," and kills himself, he has nothing left to live for, especially after the facts are revealed to him, and he realizes that there is no way out, and that he is surrounded. "A gambler with a system must be, to a greater or lesser extent, insane." It turns out Morgan and Garcia only shared popcorn and watched a movie and did nothing more. He slept on the couch, and thus there were no fireworks, unlike the insinuations. It's really not too surprising, as anything otherwise wouldn’t have been consistent with the tone of the show. Once that's cleared up, Garcia joins Kevin for their standing date every Tuesday, which they put into effect after their fight. They're going to be fine, as the end of the episode hints. The episode ends.