Morgan interviews Giuseppe Montolo, the hitman who first alerted the BAU to the pending executions of a group he referred to as "The Dirty Dozen".

Montolo tells Morgan there are four other hitmen. Morgan asks who him the "Dirty Dozen" are. Montolo tells him it's not a who but a what.  Morgan asks him to clarify. Montolo begins to choke and to spit up blood. He dies.

Morgan learns that Montolo was poisoned by a prison guard, who was later found shot to death in his car.

Rossi's daughter Joy comes into the BAU to talk about a series of missing girls from various campuses. She tells him that she put out an alert on campus chatrooms. Someone called her about a missing girl named Bahni Desai, who went missing the night before from Judy Temple College.

Reid and Morgan find two identical text books in Bahni's room, suggesting that she was likely in her room studying with the other person, Paddy Morris.

Paddy tells Morgan and Reid that Bahni left her phone in her room because they went out to a party, and didn't want to take their purses. She tells them that Bahni left the party alone.

The BAU trace Bahni's movement as she stumbled down a street. The security camera captures a shot of a man as he moves to follow her.

The unsub sneaks up the stairs at his father's house carrying Bahni on his shoulder. He puts her in a trunk in his room, then locks it.

He gets Bahni out of the trunk and puts a collar around her neck. He warns her not to scream or he'll kill her. The unsub's father yells up the stairs, telling him to get some food for him.

The unsub tells Bahni this is her room now. He sets up a remote camera so he can watch her on his cell phone.

Reid tells JJ that his mother isn't doing well with her schizophrenia, and that the doctors have to change her meds three times in the last few weeks.

The unsub accidentally spills beer on his father's TV tray. The father (Parson) becomes enraged and knocks his dinner on the floor, yelling at the unsub to clean it up. The unsub leaves the house.

A man named Sam Burnett comes into the BAU claiming to be the guy in the video. Rossi brings him in for questioning. JJ joins them.

Burnett tells them that he moonlights as a sober driver for people who drink and don't want to drive. He says he followed Bahni intending to see if she wanted a ride, but that another man stepped out and walked off with her. He says it seemed like they knew each other.

JJ asks him why he stepped back and let Bahni go by before following her. He becomes angry at this question. They release him.

Joy angrily confronts Rossi for not arrest Burneet. She decides to out for some air.

Rossi later asks where she is, and they realize that she's gone after Burnett. Garcia determines that Burnett went to the same college as Joy and left when the first girl went missing.

The team realizes they're dealing with two unsubs, one of whom is Burnett.

Garcia pings both Burnett and Joy's phone and discovers they're both together at the same alley where Bahni was abducted.

Joy pretends to be interviewing Burnett for a magazine. He tells her that he saw the unsub and Bahni, and that he "saw everything". He leads Joy down the alley and then grabs her.

The BAU shows up at the alley and arrest Burnett.

Joy tells Rossi the reason she's so concerned about Bahni. She tells him the story about how, a week before the first girl was abducted, she was attacked by a man in a ski mask while walking home drunk after a frat party.  She says he threw her into a bush, and she managed to scratch him and jab his eye before escaping.

The reason this case is so important is that she didn't report her attacker, and then a week later a girl went missing.

Garcia identifies the unsub as a Chinese food delivery guy named Tom Larson.

Bahni attacks the unsub. They struggle. The unsub's father comes into the room. The father says they need to get rid of her.

The unsub's father attacks Bahni. The unsub chokes his father and kills him.

Rossi and JJ barge in, and arrest the unsub.

JJ and Rossi confront Barnett with evidence that he killed the other three missing girls.

Rossi finds out that Joy has taken his last name for her byline.

JJ tells Morgan that someone has been stalking her on the dark net, and that she is identified to them as "the Dirty Dozen" - which refers to the botnets she's been using.