Severide, still stinging from Keeler's release, heeds his impatience with Chicago P.D. and decides to exact justice on his own. He recruits a few others on the down low, eager for revenge on the man who kidnapped Katie. What he doesn't expect, though, is a visit from his dad, Benny - once again experiencing marital problems and shocked when he hears Keeler's free. Benny asks to get involved, but Severide shuts him out - too little, too late.
Otis catches wind of Severide's secret plan and, heartbroken and frustrated, demands to help the cause. As Severide explains why Otis should stay back, Lindsay interrupts them - are they planning to take the law into their own hands? Severide backpedals, but Lindsay's no dummy - she promises to toss Severide in lockup if she catches even a whiff of revenge. He and the others take note.
Meanwhile, with her ankle mostly healed, Dawson rejoins the firehouse feeling awkward and defeated. Adding insult to injury is the presence of her fellow trainee Jones, ready to impress as Truck 81's latest candidate. Her first day gets off to a rough start when, much to Casey's chagrin, she cracks a saw blade during a rescue attempt. She annoys the firehouse even more by demanding someone on Squad run drills with her during down time, a request Herrmann reroutes to a more candidate-appropriate task: mop duty in the showers. Making matters worse, after Jones spies Dawson and Casey together, she warns Dawson not to sabotage her candidacy. Dawson takes the affront personally and makes the same argument Herrmann, Mouch and Cruz echo to him in private - Jones is entitled and cocky. Casey agrees, but believes she deserves a chance nonetheless.
But Jones' real issue is talking; in an attempt to gain respect and build rapport, she teases the other squad members. This catches the watchful eye of Severide who reminds her of the two main tenants of being a candidate: do your job and keep your mouth shut. Jones is failing point number two. Big time.
However, Jones isn't alone - an off-hand comment from Mouch to Connie, Boden's prickly secretary, results in the relocation of his prized possession, the couch. Its absence drives him crazy, and he seeks advice from Boden, only to have the chief shrug in response. So he makes a peace offering in the form of a small cactus and a full apology. His couch magically reappears in its rightful place a few hours later.
A major high-rise fire sends 51 downtown and seems like the perfect opportunity for Jones to redeem herself. With the elevators on the fritz, the whole squad hikes up 18 flights of stairs carrying all their gear, only to find a raging fire within and a wealth of victims inside. Jones struggles to keep her cool as she learns the differences between reality and training. With Casey and Herrmann's help, she manages to make it through, but the experience serves as a humble reminder of her place on Squad.
Later, everyone ends up at Molly's for a relaxing pint - until Lindsay snakes her way over to Severide to deliver some unsettling news. CPD found Keeler's vehicle with the keys in the ignition... and no Keeler. He disappeared.