Larisa Polonsky

Sherlock and Watson investigate a child abduction case involving a serial killer known as "The Balloon Man."

Alicia represents a stripper who was raped at a stag party and may have previously been abused by her husband. Alicia and her husband Peter discuss whether the children should be allowed to visit him while he's in prison, and Alicia finds incriminating pictures of Peter that her kids had hidden to save her from further pain.

Lt Severide is targeted by an arsonist, Battalion Chief Boden clashes with Gail McLeod on the anniversary of Andy's death, Shay has suspicions, and Mari visits Mouch.

Lt Casey must work with Voight and the Intelligence Unit, Shay grows increasingly excited about the prospect of motherhood, and everyone comes together to support the opening of Molly's.

The shooting of a child in their neighbourhood forces Cruz and his brother to think about the gang, Isabella gets Mills to dress up for a gala, Casey feels sad he will be seeing Dawson less, and Shay gets in deeper with Devon.

Severide is on edge after the arson attack, fearing what might be in store next. Shay and Dawson, meanwhile, plan to party away their problems.