Nat suffers a concussion when she and Barry get caught in a drive by after dropping off a patient at a rehab facility. She refuses Will's help and insistence that she go home, ignoring her symptoms and becoming more irritable throughout the day. Her mood isn't helped by the fact that she's treating a 14 year old who is married to a fifty year old man. The husband refuses to let Nat talk to her patient alone, and refuses to let the doctors treat the uterine cancer that they find during their examination. Nat finally goes off on the reverend before vomiting and passing out. Will picks up the baton on the case though, and manages to distract the husband with paperwork long enough to talk to the girl. She decides she wants a hysterectomy instead of the less aggressive approach of chemo -- not only does she want the cancer gone, but she never wants to have children. Her husband objects and is surprised that Will worked around him.
Barry is also injured during the gun fight, but the graze to his leg is just the start of his troubles. Although he turns over his gun and permit once Olinsky arrives at the hospital, an injured man comes in later with a bullet from Barry's gun in his chest. Connor manages to save the man's life, but the trouble still isn't over. There's an issue with Barry's concealed carry permit, and he's taken away in handcuffs. Maggie is shocked to find out that Barry's real name isn't Barry -- he changed his identity at some point to cover up a juvenile record. Because he didn't disclose that on his permit application, he's in serious trouble.
Connor brings his one night stand into the hospital after she complains of chest pains, and is shocked to find out that not only did she have cocaine in her system, but that she's married. Latham refuses to allow Connor to perform the surgery because of his involvement with the patient, giving it to Ava instead. Connor's upset at first, but the awkwardness when he is thanked by his date's husband for saving her life makes it pretty clear it was the right call. Even after that experience, he still agrees to go for a drink with the State's Attorney -- after making sure she's not married that is.
Sarah seems to be doing well with her treatment...until she acts recklessly while treating a patient. A man comes in insisting that he be committed because he can't stop thinking about hurting his pregnant wife, and Daniel wants to take a conservative treatment approach. His plan is admit the man and give him a safe space to work through his feelings. But Sarah's success with exposure therapy leads her to lock herself in a room with the patient and a variety of weapons -- against Daniel's explicit instructions. The exposure therapy works for the patient, but Daniel is outraged and threatens to suspend Sarah if she disobeys orders again.