Shay corners Severide in the locker room to let him know that everything regarding her pregnancy is proceeding according to plan. Severide shares Shay's enthusiasm. The crew is called out to a rescue in which a warehouse worker is buried under a collapsed shelving unit. The victim is in shock, and the team quickly begins digging the victim out, accidentally starting a small chemical fire in the process. Luckily, Mills comes up with a quick solution to get the victim out of harm's way.
Back at the station, Mills is already tagging along with Severide and the Squad team. The tension is beginning to mount, and the non-Squad team is beginning to turn on Mills. Meanwhile, Dawson and Shay's new ride-along EMT expresses an interest in Severide. Mills speaks privately with Casey, where he explains his interest in joining Squad. Casey warns Mills that he's not on Squad yet, and he needs to pay attention to his truck duties.
Dawson and Shay respond to a call to find a man stuck in an automatic garage door opener. The man is quickly bleeding out, and the team doesn't have time to wait for a truck to arrive. They'll have to cut the victim out themselves. EMT's new ride-along, Tara, is clearly not comfortable with the blood and guts that Dawson and Shay encounter on a daily basis. She may not be cut out for the job after all.
At the station, Severide continues to take Mills under his wing, and frustrations continue to grow within the Truck team. Casey talks to Boden about Mills' ambitions, subtly accusing Boden of favoring Mills to make up for his father's death. Later, Mills confides in Dawson, telling her that he knows everyone's upset with him. Dawson tells Mills to take care of himself and forget about the other guys.
The local chief stops by to interview Dawson about Tara's performance, and Dawson reluctantly tells him the truth: Tara doesn't have the stomach for a busy firehouse in the city. Later, Tara surprises Severide at his apartment. After Severide misses an appointment at the insemination clinic, Shay returns home to find Severide with Tara. Upset, she tells Severide that she doesn't want his sperm anymore.
After cutting into the abandoned house, Casey and Severide notice a strange smell and discover that the abandoned building has been converted into a marijuana grow house. When they breech the building, they find themselves in a forest of marijuana plants. Severide rescues an unconscious farmer, but one of his Squad members gets electrocuted in the house. As the fire grows, Mills and Casey drag the Squad member to safety. Mills begins to realize that he can learn a lot from Casey.
Casey's Truck team is called to a shooting incident nearby. Shay and Dawson arrive on the scene first and discover that the victim is one of Voight's enemies. Later, the whole crew meets at Molly's to celebrate the refurbishing. Severide and Shay apologize to each other, and Severide convinces Shay that he still wants to help her have a baby. At the celebration, Dawson finds that she's still torn between Mills and Casey.
Chief Boden calls Severide to the station to inform him that Tara is pressing charges, saying that he lured her to his apartment and then sexually assaulted her. It's a bogus charge, but Boden advises Severide to get a lawyer. Meanwhile, Casey and Dawson are sharing a touching moment, when Hallie stops by the bar to tell Casey that she's back in town.