Antonio, Ruzek, and Halstead all help investigate when a friend of Voight's appears to have been murdered by a serial killer. 

Lindsay is not letting it go, the IA business with Voight, because she remembers the day he and Camille took her in and they said truth was all on the table. He should have told her because she would have told him.

It seems Voight's friends are being killed. One body is a poker buddy and the next is a man Voight grew up with. The word is out about Voight working with IA. Hank pushes it with his old friend at the club. The two dead guys were shakin' down a dry cleaner. 

Looking for clues, they stumble upon a young girl, bloodied, in the trunk of a car. A white dude was there and shot her dad right in front of her. When he turned the gun on her with the same look on her eyes, she said please don't kill me and he told her to get into the trunk.

Ruzek doesn't know how to use the new composite software that just came out. It's not great timing.

Everybody is connected by some kind of holding company.

Voight goes through old pictures of him and his friends when they were kids. He keeps them in his office.

He goes to see his friend's widow to ask if the other two guys ever came around and what she knew about Maxwell investments.

There is someone named Enrietto and Hank asks about them, but she won't talk. 

Lindsay meets with her mom. She's very proud of Lindsay. She's been sober for seven months and has done the 9th step with everyone but her. She brings up Hank and reminds Lindsay that he's not her blood. She is.

Halstead is at a bar chatting with the bartender when he gets a call. He rushes home and finds his apartment has been broken into.

Ruzek is really good with the daughter of the victim. He tries to get her to go home, but when she won't at least eat.

Dale Hanson's son was at the hospital and is the guy Claudette saw. His name is Nate Hanson. There is a shotgun missing from the tack box. Nate saw Dale cower and beg for his life when he was beat up and the last guy on the list is Enrietto.

The team arrives at Enrietto's and hear gunshots. He's on the ground. Next thing he and Voight are gun to gun. The kid thought he'd go down easy.

Halstead is in the target of Nate Hanson. Halstead talks him down and takes off after him on foot. Halstead doesn't know the kid's story and Lindsay and Atwater run after him. All three almost get hit my a train. 

Nate heads to the hospital, shotgun in hand, to see his mother.Halstead assures him as a fellow Vet, he knows that he was trained to protect and doing what he believes is right. Halstead talks him off the ledge and puts him under arrest.

He put a dollar bill on the chests of his victims because if they wanted their money, they could have it. His sister is shocked that Halstead lied to Nate about not being charged as an adult. He would do anything to get the gun out of his hands so he didn't kill again.

Lindsay remembers some pretty bad times. She meets her mother's fiance. It's awkward.

Listening to Enrietto talk about their dead friend Nick and how he tried to get him to go hang with him and be a policeman but chose the risks with Donny instead doesn't play well for Voight.

Halstead wants to crash with Lindsay until the bounty blows over. Just after she says they'll work on it, a gunman shoot at him, but he gets Halstead's bartender friend instead.