Stabler and Benson investigate the murder of a 14-year-old girl found in the river. There are signs of torture on the young body and Warner tells them that she doesn't know her identity, but can tell them she's been in the United States less than four months and before that was in the Ukraine. Both Stabler and Benson realize the victim was probably part of a sex trafficking ring.
Warner points the detectives to a shelter for women who have escaped sex trafficking. From there, they find Veronica, a scared woman from the Ukraine who is in hiding from her sex traffickers. They hope Veronica can help identify their victim. Veronica tells them that her pimp would never talk to a cop, giving Benson an idea.
Benson goes undercover as a businesswoman from Chicago looking for international prostitutes for her clients. She meets with Veronica's pimp, Alec. He sets Benson up to meet the girls and when a deal is on the table, the police bust in and arrest him. He swears he has no ties to the dead body found in the river. But, he does recognize her.
Alec informs Benson and Stabler that the victim is named Elsa and she's well known in the Ukraine as being a genius and attended school in Manhattan at Morewood, an academy for gifted students. Elsa was a United States citizen, but spent time in the Ukraine visiting her grandparents. The detectives question the school about Elsa. They want answers on why her body was covered in scars and burn marks.
Benson and Stabler interview Elsa's roommate, Jennifer, who mentions that Elsa had been sneaking out recently at night, but would never allow Jennifer to come along. Jennifer shows the detectives a bag of clothes Elsa would change into before sneaking off. Jennifer says Elsa would never talk about what she did at night, but would return with bruises and burns on her skin. The detectives decide to talk to Elsa's parents.
Elsa's parents prove to be no help to the detectives. Her mother stays quiet as Elsa's father continues to talk about how he would never do anything to harm his prized child. Stabler and Benson head back to the SVU and remain suspicious about Elsa's father. Katrinka, Elsa's sister, offers up information to the detectives. She claims she was labeled a misfit when she proved she wasn't as smart as her sister. She shows the detectives her father's makeshift classroom he created for his daughters in the basement of their house.
Katrinka says she ran away to escape her father's emotional and physical abuse, but always wished she could have come back for Elsa. The detectives learn that Elsa's family received money for Elsa's enrollment into Morewood and bring her parents in for questioning. From there, they learn Elsa's father lied about having a PhD, and he also has a notorious gambling problem.
After Elsa's father tries to kill himself, he's taken to the hospital. Fin shows Benson and Stabler surveillance camera photos of her father at a casino in Atlantic City during the time of her murder, clearing him as a suspect. The detectives go back to Morewood to interrogate Elsa's classmates. From there, they find out that Elsa was into a 23-year-old graduate of the school, Danny. Stabler and Benson interview Danny, who claims Elsa was too young for his interests, but viewed himself as someone she could look up to.
Danny tells Benson and Stabler that Elsa would never be caught dead in the clothes they were describing in the bag. He also lets them know that Jennifer was always jealous of her roommate and they should really be talking to her. They go back to Morewood to find Jennifer and she calls for her mom.
Jennifer is met with her mom back at the SVU. Jennifer breaks down and admits that Elsa never talked to her when they were roommates. So, finally Jennifer broke down and followed her on the ferry and snapped. On the ferry, she murdered Elsa by stabbing her and then pushing her into the river.
Because of Jennifer's young age, Benson and Stabler fear she won't be able to handle adult prison. Unfortunately, because the ferry was crossing New Jersey at the time of Elsa's death, the case is out of their hands. They travel to New Jersey in hopes of convincing the DA to put Jennifer's case through juvenile court, but their pleas fall on deaf ears.
The DA calls both Benson and Stabler to the stand as witnesses to Jennifer's confession. Both detectives urge the Court to consider the fact that Jennifer may have the brain of an adult, but the emotions of a child. The DA notes that Jennifer was clever enough to manipulate the detectives during their investigation. The judge's ruling is to have Jennifer tried in a New Jersey adult court. After the verdict, Jennifer snaps and begins acting hysterical. Police carry her out of the courtroom.
Benson follows Jennifer to her jail cell. Jennifer admits she has no idea what's going on and confesses she's gone days without sleeping. She tells Benson that Morewood even helped her get ahold of the prescription drugs she was taking, so she wouldn't sleep. The day she killed Elsa, she was up for six days straight. She pleads with Benson to bring her pills to her, because her brain is falling apart without them.
Warner tells Benson that if Jennifer was taking the prescription pills to fight off sleep, by the time she was on six days of no sleep, she could be labeled insane. Benson rushes to the New Jersey DA's office to try to get them to accept an insanity plea from Jennifer. The DA agrees to listen to Benson and is shocked when she sees all of Jennifer's inept journal entries she made on her days of sleep deprivation. The next day, the judge accepts the DA's plea to have Jennifer be placed in a juvenile prison until she's 21.