A Halloween turns tragic when a fiancée is killed at a bar. The investigation proves difficult when it's discovered all suspects were in costume.
Responding to a call about a suspicious duffle bag at the Chicago Lakefront, Voight (Jason Beghe) is horrified to discover that the bag contains the frigid and unmoving body of a newborn baby. Determined to find the culprit who abandoned the infant, Intelligence receives a promising lead based on information provided by Chicago Med and Ruzek (Patrick Flueger) helps zero in on a potential suspect. Meanwhile, Voight is surprised to hear that his son is in town and Burgess (Marina Squerciati) and Roman (Brian Geraghty) grow closer.
Two Tulsa brothers fight for more than 20 years to prove their innocence after they were wrongfully convicted for separate murders.
While out on a bank run for his off-duty security job at the dispensary, Halstead (Jesse Lee Soffer) and his co-workers find themselves under attack by a violent robbery crew which quickly becomes a full-scale shootout. Voight (Jason Beghe) and Lindsay (Sophia Bush) question the owner of the dispensary who mentions her business has received threats from local gangs upset she's cutting into their revenue. Meanwhile Roman (Brian Geraghty), Burgess (Marina Squerciati), Antonio (Jon Seda), Halstead, Ruzek (Patrick Flueger) and Atwater (LaRoyce Hawkins) follow-up on a lead and track down a potential suspect.
Dateline updates the case of Eric Glisson who was convicted of a 1995 murder in the Bronx, along with five other people. He served nearly two decades in jail before being released because the sole witness against him was found to be unreliable. Since his release Glisson has tried to reconnect with his family, has welcomed the birth of a new baby daughter, and has filed a lawsuit against both the state and city of New York for his wrongful conviction.
After infamous criminal Gregory Yates (guest star Dallas Roberts) escapes from a New York prison, Lindsay (Sophia Bush) and the team learn that he intends to flee New York and is headed for Chicago. The SVU team informs Intelligence that Yates has been gathering information on Lindsay and after Platt (Amy Morton) calls in a triple homicide likely at the hand of Yates, Benson (guest star Mariska Hargitay) and Fin (guest star Ice-T) catch the next plane to Chicago. Upon investigation of the crime scene, the team learns that another tenant in the building is missing and they work to find a connection between Yates and the woman.
A wife calls 911 to report her husband has been shot on a country road in Texas. Could the dramatic police footage from the scene end up being key in the investigation? Josh Mankiewicz reports.
After a luxury condo is robbed, the team is shocked to learn that not only was the family fast asleep when the crime occurred, but their teenaged daughter was violated during the invasion as well. Voight (Jason Beghe) consults Jimmy (guest star Steven R. McQueen) from Firehouse 51 to confirm his suspicion that the family was knocked out by a powerful gas and Lindsay (Sophia Bush), Halstead (Jesse Lee Soffer), Atwater (LaRoyce Hawkins) and Ruzek (Patrick Flueger) go undercover to seek out the perpetrators. Meanwhile, Voight tries to help a former acquaintance get back on his feet and Platt (Amy Morton) and Mouch (guest star Christian Stolte) receive disappointing news regarding their upcoming wedding.
When a soldier vanishes from Fort Hood, her family do everything they can to bring attention to her disappearance; Secretary of the Army Ryan McCarthy speaks about the investigation and allegations of sexual assault in the military.
When Intelligence follows up on a tip Antonio (Jon Seda) and Halstead (Jesse Lee Soffer) received from a reliable informant about an upcoming drug trade, the team is shocked to discover the mutilated body of a man. Upon further investigation, the body is identified as a government official and when Olinksy (Elias Koteas), Ruzek (Patrick Flueger), Lindsay (Sophia Bush) and Halstead question the man's acquaintances they discover he had access to very important devices. Meanwhile, Burgess (Marina Squerciati) helps plan a surprise for Platt (Amy Morton).
The disappearance of a 20-year-old honors student ends up taking decades to solve.
After a botched undercover job, Ruzek is under scrutiny by the new Street Deputy Crowley (guest star Barbara Eve Harris) who will determine his future with the unit. A suspicious person call turns into a murder investigation when Burgess and her temporary partner Price (guest star Travis A. Knight) discover the body of a dead man in an SUV. After Mouse (guest star Samuel Hunt) identifies the victim as the owner of a security company, the unit soon realizes there might be more to his story. Halstead and Lindsay take a step forward in their relationship.