Lindsay is back living with Voight. She tells him she'll take care of Bunny.
Roman and Burgess are chasing down a suspect. Roman is lagging behind Burgess. Burgess finds a dead child in a refrigerator.
Dawson and Olinsky talk to the dead boy's parents while Ruzek and Atwater talk to neighbors.
Burgess talks to Ruzek about the needle she found in Roman's bag. He tells her that she needs to talk to him.
Olinsky talks to his daughter about wanting to get her on a plan, but she's not interested.
Lindsay and Dawson question a lead who is a former sex offender, Darren Woodhall, but he has an alibi. Halstead discovers he lied and the team investigates his house. Another guy in the house pulls a gun on Lindsay and Halstead arrests him.
Voight and Dawson question him about Woodhall and he says he's been taken. Dawson gets physical with him.
Voight and Dawson question the boy's mother to find out if her husband did something to Woodhall. She tells them and they stop catch her husband beating Woodhall.
Lindsay goes to talk to her mom and tells her that they need time apart.
Another boy has gone missing. Olinsky and Halstead follow a lead to a mechanic and find the dead body of Ray Malone in a freezer. They learn Ray was involved in the accidental shooting of a child.
They chase the suspect through the park. He has a gun to the kid's head. Dawson volunteers to talk him down. He convinces him to let the kid go. He raises his gun on Dawson, but Halstead shoots him.
Roman tells Burgess that he is a donor for a kid dying of leukemia.
Bunny tries to get Voight fired.