A teen party that became an orgy yields explicit photos that go viral. Barba's focus on prosecuting the student who posted the photographs is sidelined by a cluster of measles cases which are traced back to the same party. As the virus spreads through the city, Benson's son becomes one of the victims, and she looks into the mothers who may have falsified documents in order to enroll their kids into the school system. Elsewhere, Amaro copes with news about his son.moreless
A college student makes a rape accusation in a TV interview, claiming she was gang raped at a fraternity house. Her story casts a national spotlight on sexual assault on college campuses, but her legal case is difficult for Barba to prove.moreless
Severide's old friend arrives, hoping for a second chance with the Chicago Fire Department. Meanwhile, Mills tries to regain his active squad status, Mouch confronts his fear about meeting his child, and Brett and Dawson set out to have a big night out.moreless
A famous author whom Carisi idolizes becomes the center of a feud between his wife and two daughters. As evidence mounts against the wife, Carisi takes a personal interest in the case and the man's well-being. Elsewhere, Barba faces his own family conflict when he forces a decision on his abuela.moreless
Scanavino discovers a woman posing as a madam while he is undercover on a trafficking sting. It turns out she's there to track down her daughter, who disappeared three years ago. The team must then balance ethics and necessity as they search for her daughter while closing in on the perpetrator - an unexpectedly familiar face. Elsewhere, Benson gets disturbing news that may affect her son.moreless
There's a new chief at 51 while Chief Boden takes leave, and he brings with him a relieving firefighter who none expects they would every work with. The new chief's methods of leadership are quite different than the crews at 51 are used to ...moreless
Detective Tutuola is drawn into the online gaming world when he investigates the death and rape threats by male gamers against a female developer who is set to launch her new game. When the threats become reality for one of her employees, the team must find the perpetrator before another assault occurs.moreless
Benson and Rollins deal with the fallout after a rape suspect is released due to no evidence and the rape victim's father takes justice into his own hands.
Leslie Shay's sister visits to get some closure on her Shay's death and the investigation into her arson continues
Amaro's estranged father is arrested at his own wedding after a fight erupts, and Amaro becomes a witness in a case involving family secrets.
A 15-year-old girl, answering a social media invitation, sneaks out to meet her movie star crush. Later she is found hanging onto life in an alley after a sexual assault. Olivia believes the star is the perpetrator, but cannot find any proof against him. Proof comes in the form of missing security footage that the website posts. The site owner refuses to reveal his source, and it is up to Barba to find a way to make him do so.moreless
Rollins' old boss from Atlanta visits New York City along with his newest detective, who is found unconscious in her hotel bathroom. The rookie detective makes a rape claim, but then she recants it, leading Rollins to face a dark part of her own past.moreless
A serial rapist strikes, attacking young, petite girls during the early morning. Rollins finds a pattern between these assaults and some rape cases she worked on back in Atlanta, but the rape kits for those were never tested. Meanwhile, a judge threatens to remove Noah from Benson's home.moreless