Reid has a dinner date at a restaurant with a woman named Cat who he met online.
Cat asks Reid about his wife of four years. At that point we realize he's not on a date. He's working.
Reid negotiates with Cat to have his wife killed.
JJ and Rossi are monitoring the exchange from nearby tables.
JJ mentions that Cat's usual pattern is to take her victim (in this case, Reid) to a secondary location where she then kills them.
Cat asks to see Reid's ring. She notices that it doesn't have had dings or scratches. She tells him he's not who he says he is and he isn't married. The ring is brand new.
Cat puts her hand beneath the table and there's the click of a gun.
Reid reveals that his team has been hunting her and the other hit men in the "Dirty Dozen" gang.
Cat immediately acknowledges she knows he's part of the BAU. She says "hello" to Garcia (who is monitoring the exchange from her office).
Cat tells Reid to get JJ to leave the restaurant. Hotch relays the demand to JJ, who leaves.
Rossi remains in the restaurant, with instructions to take Cat down when he can.
Cat demands Reid's phone. She sets the timer on it for 30 minutes. She tells him he has that long to answer every question she asks.
She tells him that if he lies, she'll know. She says that if he wins, he can take her out in handcuffs. If she wins, he has to escort her out of the restaurant safely.
Her first question: how did they find her?
Reid tells her they got a big break in the case at the end of last year, which he found out about when he got back from some time off.
She asks him why he took time off.
Flashback to three days ago. Reid arrives at Morgan's place.
Savannah (Morgan's girlfriend) hands Reid an envelope about "that thing we talked about." Morgan asks what it is, and Savannah tells him it's medical stuff and "shop talk."
Cat tells Reid to stop, and that he wasn't revealing why he took time off work. He refuses to tell her. She asks why. He tells her it's not relevant to her story.
Reid explains that after he showed up for work, they learned that someone unexpected had decided to talk. It was Brian Cochrane from the NSA.
Hotch had explained that he'd put Cochrane on a 24/7 lockdown, and that he's had a breakdown when he was in solitary confinement.
Garcia and Hotch had already spoken with him. Tucker didn't know the four hit men's names but did know their areas of expertise. There's The Sniper, The Chemist who works with poison, The Bomber, and finally, the Black Widow.
Reid tells Cat they deduced that the hit men operated like spokes on a wheel. They got jobs through one intermediary named The Snowman. The Snowman happens to be an IT expert who set up the whole network on the darknet.
When they arrested Cochrane they found a flash drive that gave them to a part of the darknet that they didn't know about.
Garcia used the flash drive to locate the website that was set up for the hit men, as well as the location of the safe house where they were keeping The Snowman. They realize The Snowman is a kid.
Garcia uses flashcards to warn The Snowman that the FBI is about to raid his safe house. She warns him to get down. Just as he does, the FBI storm into the house and arrest two of the hit men: The Sniper and The Chemist.
The Chemist injects himself with something and dies.
Cat repeats her demand to know what Reid did on his time off. He refuses.
Hotch orders Rossi to take Cat down.
Rossi walks over to their table. Cat moves closer to Reid and uses the tablecloth to muffle his audio.
Cat threatens to kill Rossi if Reid doesn't reveal his secret.
Reid agrees to do so, and tells Rossi to stand down.
Reid tells her that his mother has schizophrenia, and the doctor had changed her medication, but that it seemed to agitate her. He left work to go help her.
She says Reid told the truth but kept something back. As a penalty, she added ten minutes to the counter.
Cat boasts that she has flushed out the agents in the restaurant. Tara Lewis sits at another table. She shares a toast with Morgan, takes a drink and says "guess again, bitch."
Reid explains that capturing two of the hit men made the job harder. The Snowman tells the team that he always had two of them keeping him company, but never The Bomber.
He tells her that Hotch had planned to lure out the Black Widow. The intent was to take her alive so that they could lure out The Bomber.
Reid says that the pattern they found with Cat was that she tended to kill men who had hired her to kill their wives. Her last three kills were men who had children. The kills for her were personal.
Reid tells her that her real issue is with her father, who she will never find, and that she kills men as an outlet for her rage.
The timer goes off. Cat tells Reid that her escape plan is intact, and that his entire profile contained a flaw: the assumption she was alone.
Reid realizes that The Bomber is there in the restaurant, and that a bomb has been placed.
Cat tells him that her job was to keep Reid and the team occupied on their table, so that The Bomber could get his work done.
JJ and Rossi go searching. The discover a six interconnected C4 charges in the basement, all hooked up to a city gas line. If they go off, they could take out the whole block.
Lewis instructs the kitchen and wait staff to give all guests their checks, tell them their dinners have been paid for, and that they should leave immediately. Their excuse is that there was an unforeseen problem in the kitchen.
Cat notices the activity. She tells Reid she's okay with it, because it will give her more cover as they leave together.
Hotch tells Reid that all agents are pulling back and will not apprehend her until the bomb is defused.
Cat gets up to leave, but Reid invites her to sit back down. He tells her he found her father. But he won't tell her unless she sits back down.
She sits down and tells him to finish his story.
Reid tells her that he learned her real name - Catherine Adams - due to his profiling of her.
He says that her father left the country in 1987 but returned in 2012.
Reid tells her that he found her father right there in Washington D.C., but that he was in bad shape when he found him.
He tells her he showed a picture of her to her father, who was trying to sleep in an alley, but that he didn't recognize her.
Cat tells him to complete his story about his mother.
Reid tells her that when he visited her he realized that for three seconds she didn't recognize him. He had her tested that morning, and discovered that she had early onset dementia, probably Alzheimer's.
Cat asks him if he tested himself. Then concludes he didn't because he is scared.
Reid says that he figured he dodged a bullet when he didn't have a schizophrenic break at age 30 like she did. But the onset of Alzheimer's is scarier because he can't help her.
JJ and Rossi notice that the bomb is suddenly armed.
Morgan tells everyone that Cat hasn't done anything to arm the bomb, so it must be the Bomber who's done it.
Lewis is convinced The Bomber isn't a man.
Lewis spots The Bomber. It's a woman holding a cell phone who is sitting alone at one of the tables.
Morgan takes Lewis' hand and begins to walk out, telling her loudly that he wants to take her dancing. They get behind The Bomber and wrestle the cell phone out of her hand. They disarm the bomb.
Cat gets Reid up and puts a gun to his head.
Morgan tells Cat they brought her father to the restaurant and that if she surrenders, she can not only testify against him in court for killing her mother, she can ride in the police van and "remind him who she is."
Cat agrees, on the condition that Reid escorts her out. Reid agrees. Cat drops her gun.
Reid puts her in handcuffs. He opens the van to put her in. The van is empty.
She realizes he's lied to her about her father. She promises to come after him after she's served her jail time.
Morgan asks Reid about the medical information in Savannah's envelope. He guesses it's about Reid and his quest to find out if he's going to develop dementia.
Reid replies that he's too young to be tested yet. He'll just have to wait and hope he doesn't get it.