The discovery of a beaten infant leads detectives on a search for the attacker, who may be a pedophile. When the medical evidence shows the injuries were a result of shaken baby syndrome, their focus shifts to those closest to the child: her mother, the mother's boyfriend and the nannies.

A young, emaciated boy is found by neighbors scrounging for food; detectives suspect the boy is a victim of abuse and are reluctant to let him go home.

As Benson and Stabler investigate the disappearance of a mother and her teenaged daughter, they uncover a conspiracy between a corrupt immigration attorney and gangsters running a prostitution ring that is staffed by women they have smuggled into the country and imprisoned as sex slaves.

Complications ensue in the investigation of a Stone Cold Assassins gangbanger who fell off a building after the victim that he tried to rape bit him in self-defense when the vic's twin sister cops to the crime, seemingly impossible due to the evidence until the secrets regarding the sister's true genetic identity are revealed.

Monica Phelps is found dead in her apartment, her son Nathan hiding in the closet behind her body. Detectives soon link Monica's death to philanthropist Ted Carthage, who runs an organization dedicated to helping people get off the streets. Benson is certain that Carthage is the killer, but a shaky ID from Nathan puts him back on the street. After Nathan kills Carthage himself, Sophie Devere argues that Nathan committed the killing because he saw Carthage shoot his mother -- something the gun manufacturers don't like.

A manhunt ensues when Victor Paul Gitano, a recently released sex offender, kidnaps two children after killing the rest of their family. Benson and Stabler pursue Gitano only to find their own relationship challenged as both experience opportunities where they put their personal relationship ahead of their job. After having her throat slashed, Benson requests for a new partner when she hears what Stabler has to say about their relationship and their job.

Benson and Stabler investigate a suspected child abuse case only to learn that the woman who reported it is the real case.