Stabler and Fin report to a crime scene where the lifeless body of an up-and-coming ceramics artist, Casey Chapman, was found. She was bound and tortured before being strangled. The scene is strikingly similar to another, weeks before. Back at the lab, Warner warns Stabler and Fin to find this killer fast, because he's obviously into torture and willing to increase the pain with each victim.
Back at the SVU, detective Moran from Major Case Squad shows up to take his case back. Moran notifies Stabler that the serial killer has not killed once before, but four times before. Cragen automatically feels that Moran and his squad are interfering in their case, but Moran insists this is his case and he doesn't need Stabler's help.
Stabler and Fin interview a possible witness in Casey's murder. They release a sketch of the suspect to the press. The sketch leads to Stefan, a man with petty crime in his background and carrying a lock pick kit on him. During interrogation, he tearfully swears he didn't commit any murders. Cabot has a hard time believing Stefan is their man, but says if they find a murder kit linking to him, she'll throw the book at him.
When Stabler and Fin return to the interrogation room, they find Stefan's stabbed himself in a suicide attempt over the thought of going into prison. Stabler follows the ambulance to the hospital and also sees Moran, who is there visiting his comatose 12-year-old daughter. Moran opens up to Stabler about how he lost his wife in the same car accident that put his daughter in a coma. The accident happened just after his wife accused him of caring more about this case than his own family.
Stabler accuses Moran of using all of his focus on his case as a way of dealing with the pain of what happened to his family. Because of that, Moran hasn't let anybody help him with his case and now they have five murdered women on their hands. Just when Stabler notifies Moran of a suspect in custody, Moran gets a call that another body has been found. Warner tells the detectives she was burned alive, but before that, hog-tied just like the rest of the serial killer's victims.
Stabler and Moran both believe the woman's body was burned to destroy all evidence of DNA. Before that, somebody at the SVU leaked to the press that they had the serial killer's DNA. The Captain accuses Cragen's team of messing up the case, but Moran defends the SVU. Later on, Cragen warns Moran that if he holds anything back involving the case, he will take action. Moran agrees to work as a team with Stabler.
The SVU use the DNA sample they have to trace down a list of suspects. Mark Ocurro is set apart from the rest, because they can't account for an alibi. Ocurro works for the airline, returning lost luggage. The detectives quickly learn that the victims had all just returned from some of kind of trip.
Stabler sets up a decoy to catch Ocurro in the act and it works. Ocurro returns a suitcase to an undercover agent and before he can attack her inside her apartment, Stabler arrests him on the spot. Moran finds tape, glue, handcuffs and condoms in Ocurro's van, as well as a list of all the females who reported their luggage lost with the airline.
As Ocurro is being interrogated by Moran and Stabler, Munch and Fin are searching his apartment. Inside, they find books about serial killers and autopsies. When the detectives flip his wall art around, they find photos of women hog tied and gagged. Meanwhile, Ocurro calls a lawyer. She later defends her client's taste in "art" to a judge.
At the pre-trial, Ocurro's lawyer argues the evidence against her client and says she has his mother's entire bridge club to corroborate his alibi in the last murder. If Ocurro is cleared of Casey's murder, the link tying him to other murders will be dissolved and Cabot's case ruined. Stabler and Moran question Ocurro's mother about his alibi. She confirms Ocurro's alibi, but tells the detectives her son is evil and she really wishes he would be put away for life.
Warner establishes that if Ocurro messed with the kiln temperature inside Casey's apartment, the heat could have altered her body's condition, making her time of death much earlier than documented. This was all the evidence needed to pin Ocurro as their killer. Moran and Stabler trace Ocurro down and stop him from murdering, again. In a fit of rage, Moran begins kicking Ocurro while he's handcuffed and Stabler stops him from going any further.
Later on that night, Stabler finds Moran at the hospital, knowing he would be visiting his daughter. Instead, he finds Moran in the O.R. waiting room. Stabler delivers the good news that Ocurro has confessed to the six murders, as well as two more in the Dominican Republic. Moran is relieved that they found their serial killer. Stabler learns that Moran has allowed his daughter to be taken off life support and donated her organs. He confides in Stabler that this is now his second chance to live again, and everybody needs a second chance. Moran then goes into the O.R. to say goodbye to his daughter one last time.