Lindsay wakes up in bed with Landon. She arrives at work late and hung over. 

Voight is briefing the team on Cdr Perry's nephew Carter who is undercover with drug dealers. 

Voight questions if he can count on Lindsay who insists he can. 

Lindsay questions corrupt cops that they believe robbed the dealers that Carter worked with. They insist on meeting with Voight. They make a deal.

Lindsay goes into the house with the dirty cops to retrieve the drugs and money while the rest of the team waits outside. Things go south fast when they don't get all the money and one of the guys pulls a gun on a kid. Lindsay shoots him in the arm and the team moves in to make arrests, blowing Carter's cover.

Dawson wants to buy a boxing ring and asks Halstead and Roman to invest. 

Olinsky meets with a woman he dated while he was undercover. 

The cops are released due to lack of evidence. 

Lindsay must pass a drug test after firing her weapon.

Cdr Perry is shot dead and Carter is wounded.Carter admits to Voight that he took money from one of the drug deals. 

Lindsay admits to Voight that she didn't take her drug test because she wouldn't pass. He tells her he'll have a doctor backdate a prescription for whatever pills she took and then takes her off the case. 

The team raids a club to get the guys who killed Cdr Perry. Voight questions one of them and he finds out Lindsay's in danger. 

Lindsay arrives home to Landon waiting for her. They go inside and are ambushed at gun point. 

Atwater bursts in to save Lindsay.

Voight goes after Roland who offers him a million dollars. Voight makes him turn himself in.

Voight brings Atwater back to Intelligence. 

Voight gives Dawson the money for his boxing ring. 

Ruzek proposes to Burgess and she accepts. 

Olinsky finds out he has a daughter. 

Lindsay quits.