Larisa Polonsky

When a school nurse notices several injuries on a young girl, the SVU detectives are called in to investigate. A closer look at her family reveals a mother (guest star Hope Davis) struggling to manage the violent outbursts of her nine year old son (guest star Ethan Cutkosky). As the SVU squad and the visiting Dr. Huang (BD Wong) debate an appropriate course of treatment, the situation rapidly explodes into a dangerous standoff. Meanwhile, Detective Amaro (Danny Pino) tries to establish a relationship with his newly discovered son.

When the son of a Russian gangster is killed at his own engagement party, Danny delves into the world of the Russian mob and the family politics that exist. Meanwhile, Erin is thrown into a high-profile corruption case.

Sherlock and Watson consult on a child abduction case involving a serial killer who is nicknamed "The Balloon Man," because he leaves a signature batch of balloons at each of his crime scenes.

A stripper claims she was raped at the bachelor party of a prominent businessman. Alicia represents her after the States' Attorney refuses to pursue criminal charges.

An arsonist targets Lt. Severide. Meanwhile, Station 51 is under scrutiny by Gail McLeod, a financial consultant for the city who is deciding if any firehouses should be closed. Mouch receives a visit from his Japanese girlfriend, Lt. Casey "celebrates the one-year anniversary of Andy's death, and Shay suspects Severide's paternity.

In the wake of Heather's (guest star Chaon Cross) incident, Lt. Casey (Jesse Spencer) is having a hard time handling his newfound responsibilities. Lt. Severide (Taylor Kinney) is on edge dreading the next attack from the firehouse’s arsonist. Meanwhile, with Renee (guest star Sarah Shahi) back from her mother's, Severide knows he has to confront her about his paternity suspicions. Elsewhere, Mouch (Christian Stolte) begins his campaign for union president and Shay (Lauren German) and Dawson (Monica Raymund) feel that they need to get out more.