S3, E18: While responding to a call of shots fired, Voight (Jason Beghe), Antonio (Jon Seda), Halstead (Jesse Lee Soffer) and the team come across a secret battered woman's shelter and discover the owner has been wounded and a resident of the shelter has been kidnapped. The team faces a challenge as the gunman is still at large and the identities of the women are kept confidential. Meanwhile, Burgess (Marina Squerciati) and Roman (Brian Geraghty) go undercover to track down a man robbing people by catfishing them on a dating app, and Lindsay (Sophia Bush) opens up to Halstead about her past.