Halstead enters District 21 for his shift and finds Voight and Commander Perry waiting for him. They notify him of Rodiger's murder and show off surveillance photos of Halstead's car tailing the victim. Even though he denies any involvement, Halstead hands over his badge and gun. Suspended.
With Halstead off the clock, Voight allows Sumner to test her mettle in the field as Intelligence lands a case that requires all hands on deck: a human torso found in the trunk of a wrecked car. When firefighter Kelly Severide IDs a man that fled the scene, it leads the unit to his body, this time in a vat of hydrochloric acid. The connections all point to a local gang called the Northsiders and its leader, Jacob Sims. Solid intel puts Sims at a suburban gun show so Voight organizes a sting in the parking lot. But local police move in early and Sims opens fire - killing a cop and somehow skirting arrest. What they do find is a DVD - a homemade sex tape starring Sims... and Caroline, the lawyer for the second dead body. She claims Sims threatened her with blackmail and forced her to have sex. Looks like Intelligence needs a line on Sims.
Meanwhile, Ruzek reaches out to Burgess who fired her gun for the first time during the botched suburban sting. After sharing a few beers at Molly's, they walk to Burgess' car... and end up in a kiss. Burgess backs away and later they agree to pretend it never happened.
Sumner proves her worth to the unit and hits up an informant with ties to the Northsiders. He clues her in on a meth lab operation Sims runs out of a trucking yard and sure enough, they discover him there - once again with his guns ablaze. Ruzek takes a bullet in the shootout, but Sims can't outrun Antonio and Voight. Once in custody, Sims drops some curious hints that circle back to Caroline - did she organize the whole thing? Given her recent string of failed cases and guilty clients it seems possible, but lack of evidence kicks her out of custody. Maybe Sumner will file with the DA. Either way, Voight congratulates her on good police work.
This sentiment carries over to Halstead, who - with Antonio's help in sneaking out Rodiger's homicide file and Olinsky's help in analyzing it - discovers the real murderer might be the least likely one of all. He meets with Phil Rodiger, Lonnie's son, for a beer and presents substantial evidence - Phil relents under the pressure, later sobbing out a full confession to Lindsay. Voight hands back Halstead's star, his name cleared, and the whole unit sighs with relief.
That night, Lindsay is watching TV in her apartment when a knock comes at her door. It's Severide, holding a paperweight Lindsay lost earlier in the day (a grenade from Academy). Turns out the fireman stole it as an excuse to come by - and his risk pays off with a long kiss in her doorway. And then another. And then - Lindsay cuts it off; she's got to work early tomorrow. Severide shuffles away, all smiles.