Neither Thulin nor Hess can stop thinking about the unanswered questions hanging over their case. Rosa's career unravels as a childhood memory surfaces.
Scott's future with Hooch is threatened when an investigation of a robotics lab goes wrong.
Things get a little hot in the kitchen when Tom considers ghostwriting a memoir for a celebrity chef; Connor starts dating a friend of Sarah and Denise's who makes a surprising impact on him.
The detectives find inconsistencies as they dig deeper into the Kristine Hartung investigation, as the threats against Rosa take a terrifying turn.
Vanessa and Archer disagree on how to handle the victim of a motorcycle accident; Scott and Charles deal with a UNICEF negotiator with repressed trauma; Hammer and Halstead treat a high schooler with Addison's disease and a clingy mother.
A mysterious stranger and a scavenger hunt help Archer and the gang get a jump on their enemies.
The finale. Season 23 comes to an end and one Houseguest is voted the winner of Big Brother and the grand prize of $750,000.
As state-legalized cannabis spreads, NOVA explores its little-known risks and benefits.
Immunity challenges get interesting when a new idol is introduced that has a special twist.
After the Veterans threaten the Rookies, one Rookie comes up with a plan to detonate the Veteran's stronghold. Berna calls out all of her rivals in an explosive manner. The competitors take on the deep seas during the "Dive Bomb" mission.
Refusing to accept what's going on around her, Alice creates an imaginary musical fantasy world in which the Coopers are one big happy family again. Veronica and Archie make a big decision about their future.
A video of Casey from the roof goes viral. Mouch sets up a Little Free Library at Firehouse 51. Herrmann breaks protocol.
Adam is ready to leave the struggles of his high school years behind him but is distraught to discover he's been waitlisted at NYU.
Singers from all walks of life become the stars they've always wanted to be. They'll be given the chance to show how they've always wanted to be seen, creating their dream avatar Alter Ego.
While Dean reckons with his first taste of heartbreak and betrayal, the adults in his life are overly empathetic and assume his grief is from mourning current events.
The Clan digs deep to make the perfect record to take the industry by storm.
Thulin and her reluctant new partner Hess, investigate a gruesome murder. Politician Rosa Hartung returns to work after her daughter's disappearance.
Hess uses unorthodox methods to prove a theory about the Hartung case. The detectives chase a lead linked to a text message as Rosa faces another threat.