In the Season 3 finale, tensions at 51 cause a shake-up at the station, and Casey dives deeper into the case against Nesbitt. Scottie Pippen guest stars.
Picking up right where the last episode left off, Nesbitt's team inspects Casey's phone... and determines it's clean. It turns out Casey tossed the wire in the bathroom before the men frisked him. Either way, when he meets up with Chicago P.D., he regrets to inform them that Nesbitt and his associates didn't discuss anything of value. This case is far from over.
Back at 51, Rice apologizes for how he reacted to Severide's question on ducking, but still maintains his innocence in the matter. This does little to quell the firehouse tensions, which intensify after a gas leak call pushes both Truck and Squad to prove their mettle to each other - and in the process they almost botch a rescue. Animosity reaches a tipping point, exemplified by Otis leading the Truck team to make a show of sitting down at the Squad's table, and a war of words between Casey and Severide. Boden laments the station's situation to Donna and she provides excellent advice - lead through action, not words.
Meanwhile, Chili receives the prototype for Chileeze and it sparks a great idea from Herrmann - they need a celebrity spokesperson. This leads them to a hotel lobby, and with a great assist from Otis, they trap Chicago Bulls legend Scottie Pippen in the elevator. Chili gives him the Chileeze pitch - and Pippen agrees to participate. Everything appears to line up for an awesome business venture, until Herrmann and Chili make a devastating discovery later at Molly's - another competitor beat them to the market! Chileeze will have to go on ice.
Still concerned about the situation at Stilletos, Casey comes clean to Boden about his undercover assignment with Chicago P.D.'s Intelligence unit and requests to take off his next shift. Voight and Antonio provide support for his cause, explaining how Stilletos acts as a criminal front... but the discussion occurs in plain sight, where a spying Nesbitt sees the whole thing. The next time Casey visits the club, Nesbitt suggests Casey's collusion with the police, and the lieutenant flat-out denies any association. Nesbitt plays dumb despite the lies and asks Casey to meet him later that night.
Another lie rises to the surface when Severide learns that Rice never took any equipment to the shop. In Boden's office, Severide calls in Rice and removes his friend from Squad, effective immediately. Rice finally confesses to ducking calls in an effort to remain safe for his family, but the excuse fails to impress Boden or Severide. After all, risking their lives is part of the job. Rice's dismissal causes a shake-up at the firehouse - Boden announces that Cruz will assume Rice's spot on Squad and Otis will drive the truck, Cruz's old responsibility. With Casey out, Boden takes over as interim lieutenant.
Before the team has time to react to the changes, a call sends them out to a fire in progress with a handful of fellow firefighters and civilians trapped inside. Severide and Dawson both rush to save the victims, but soon find themselves trapped - and with only one working oxygen mask. The fire rages on, and Boden demands that the rest of the team remain outside while he ventures in, determined to rescue Severide and Dawson. As time passes and no one emerges, another chief calls the rescue attempt over. Cruz, certain that they should wait longer, threatens the chief with physical harm unless he stands down the order. Other firefighters pull him away, and the squads spray water onto the building, ending any hope for those inside. But moments later Cruz is vindicated when Boden, Severide and Dawson emerge from the building - out of breath, overheated and unharmed.
Chief Tiberg awaits 51's return from the fire and asks to know the name of the culprit who threatened the other station chief with violence. But before Cruz can confess, Otis steps forward. And then Severide. And Mouch. Soon the whole team, both Squad and Truck, confesses to threatening the chief. Tiberg exits without a name and Boden suggests he stop asking. Regardless, this moment reunites the firehouse, and the whole gang heads to Molly's to celebrate. They're joined by Roman from Chicago P.D., who takes a shine to Brett... and at the end of the night the two wind up at Roman's apartment locking lips and shedding their clothes.
The end of Dawson's night takes a different spin. Feeling sick to her stomach all day, Dawson leaves her shift at Molly's early and winds up in the bathroom with a pregnancy test in her hand. She stares at the results and rushes to Casey's apartment... where she finds the door already open. Dawson enters and calls out his name, but no one responds. As she walks through the apartment, she notices signs of some kind of struggle, and soon finds the likely result - a woman on the floor, unmoving, next to a rug soaked in her blood. It's Katya from Stilletos. And she looks dead.