Nick Wechsler

Reese throws a party at home when Hal and Lois take a romantic break, but the delinquent friends of Francis gatecrash and hold the boys hostage.

The waitress is getting married and Dee is jealous that she's beating her to the altar, so she tries to derail the wedding.

After the body of a young woman is found with multiple gunshot wounds, Intelligence identify links to other deaths and realise they are dealing with a serial killer; Lindsay finally meets her biological father.

When Olinsky catches wind of a grieving father looking to avenge his daughter's death, he goes undercover as a hit man.

The gang's high school reunion has come at last; each of them recalls the events that shaped them into the people they are now.

Halstead goes undercover to investigate the death of a teen who ran away from a treatment centre for troubled girls.