Voight and Lindsay celebrate Daniel's first birthday with Justin. 

They get called to a murder victim, Melissa, found in a trunk with her throat cut. 

Voight is offered a promotion to lieutenant. He thinks the reasoning is to take proactive cops off the street. He has 48 hours to decide. 

Roman says his goodbyes on his last day. 

Olinsky talks to Melissa's father who said she'd been different recently.

Burgess tells Roman she's staying. 

Mouse discovers that Melissa knew Justin. 

Voight and Lindsay find Justin shot in his trunk. They rush him to the hospital. 

Voight sends everyone to question CIs and get answers at any cost. 

Ruzek says it sounds like Melissa was involved in home invasions, and that maybe Justin knew about them. 

Dawson finds a lead to a suspect and they question him. He gives them a name to the shooter, Kevin. 

Crowley tells Voight his unit can't actively pursue this case. 

Sharon comes to the station to tell Voight that Justin will never wake up. Olive wants to withdraw life support, but wanted Sharon to ask Voight first. 

Crowley tells Dawson that when Voight ends up on charges, she'll need someone to run Intelligence. Dawson says no. 

Lindsay realizes Voight sent the team to the wrong place. She goes after Voight. 

Voight has the killer tied up. He tells him he didn't do it. Voight unties him and tells him to start digging. 

Lindsay shows up and begs Voight not to do this. Voight tells her to leave, and she reluctantly does. 

Voight shoots him and buries the body.