It is evening as Prentiss enters The Black Shamrock. She remembers how she met Ian Doyle in the same bar during her days with Interpol.
Back in the BAU, Morgan points out the list of Interpol operatives who worked Ian Doyle's case had the initials LR. Garcia realizes that a name was missing and that's when Reid remembers Prentiss said "Lauren Reynolds is dead" when he inadvertently overheard her phone conversation. They suppose Prentiss would be a target, but she had left her gun and badge in the BAU and there was no way to contact her. Rossi concludes Prentiss ran to protect them from Ian Doyle.
Prentiss shoots Jack Fahey in his car as she tries to extract information from him.
Agent Jareau returns to the BAU to help them find Prentiss. She tells the team that Emily had been a member of a special taskforce, JTF-12, which was primarily formed to deliver a profile of terrorists. Apparently only Clyde Easter and Prentiss remained alive after Ian Doyle had killed each member of JTF-12. Prentiss, as Lauren Reynolds, had posed as a weapons dealer to get intel on Valhalla. As part of her cover, she had established a personal relationship with Doyle.
Morgan and Rossi pay a visit to Prentiss' apartment. Morgan is visibly upset that Prentiss had kept secrets from them. Rossi sees a gold gimmel ring, a ring that is meant for an engaged couple, that had been tossed into the toilet, but was too heavy to be flushed out all the way.
Memories of the gimmel ring that Doyle had given Prentiss/Lauren Reynolds preoccupies her memories.
Garcia leaves a touching message for Prentiss on her cell phone and tells her they will come to help her if they knew where she was.
At The Black Shamrock, Prentiss fires her gun at Doyle's car and leaves a grenade inside. However, Doyle knew she would be there and was waiting. He shoots back and captures her. He takes her to the cellar where he ties her up and tattoos a four-leaf clover on her chest.
Clyde Easter is detained by the FBI. Hotch asks him to help the team find Prentiss.
Rossi and Reid interrogate Jack Fahey. He stoically insists that he will not give in. On the rooftop, Rossi and Seaver attempt to make him talk, but Fahey is shot by a sniper.
Doyle's cohort shows Prentiss a video showing an aerial target against Rossi, Seaver, and Fahey. Prentiss suggested that Fahey be shot instead of her team, and it was done.
Rossi demands that Seaver try to profile Prentiss. After some hesitation, she says she believes it was strange that Doyle killed a child in DC.
Clyde Easter challenges Hotch to kill Doyle. He declined. Easter then cooperates in profiling Doyle.
In the cellar, Doyle points his gun at Prentiss. She remembers Doyle had a son he named Declan. The housekeeper had posed as Declan's mother to protect the child, so no one could use him against Doyle. Doyle shows Prentiss where Declan had died. Prentiss admits the photo that shows Declan and the housekeeper dead was staged. Doyle beats her repeatedly.
Morgan and Hotch arrive at The Black Shampoo with operatives to save Prentiss. However, Doyle has stabbed her in the chest with a pointed stick. As Morgan leans over her, he can see she is barely breathing. EMS takes her to the hospital.
The team members wait anxiously for news about Prentiss in the hospital waiting room. JJ enters with a remorseful expression and tells them that she never made it off the table. Hotch and JJ leave the room and go into the hall, and exchange knowing looks as the rest of the team cries.
In the cemetery at her funeral, Special Agent Emily Prentiss' tombstone reads:
October 12, 1970-March 7, 2011
In Paris, JJ meets with a woman wearing a trench coat and gives her passports for three different countries and bank accounts. The woman speaks and sounds like Prentiss. She thanks JJ and walks away into the Paris night.