A family heads into a movie theater when a people come running out and gunshots are heard. The family is separated. The ER staff orders lunch at the truck on Connor, while Nat suffers through food from her mother-in-law. April muses that there's something going on between Nat and Will. Maggie runs out and tells them about the shooting. Sharon makes sure that the emergency procedures go into effect. Chili and Brett bring in the mom and the little boy from before. The boy is perfectly fine, but the mother is in bradychardia.
The ER is crowded with victims, and Sharon tells Charles that the shooter is on his way to Chicago Med. The husband comes in looking for his family, and Maggie takes him to the little boy. Will and Connor get the mother back and Will is worried about how long she was down. Nat treats a teenage girl with an overbearing mother. A new patient is brought in and Will wants to know if it's the shooter. The EMTs confirm, and Will is reluctant to do more than absolutely necessary, and thinks that Connor is wasting his time. Neurology checks on the mother from the theater, and delivers the bad news to Will.
Lucy Sims husband has agreed to organ donation, and Sharon arranges the details. The man who shot the shooter arrives at the ER to applause from other victims, and Will expresses his admiration. Connor and Zanetti work on the shooter in the ER, and he snaps at a nurse who makes a comment about the kid. Nat talks to Charles about her patient and her suspicions of anorexia. He proposes a new "anti-nasuea" medicine to help the girl eat. Maggie notices that the only gun shot victim is the supposed shooter. Will and April treat an elderly (mildly racist) woman who lied about being in the theater. The supposed hero gets stitched up and talks to the April and Sarah about how he suddenly has more followers. Sharon takes him to her office to spick to Lindsay and Halstead about the incident. He tells them that the kid came in through emergency exit and claims that kid was waving a gun around. Lindsay reveals that the kid didn't have a gun but a leaf blower. He was trying to film a prank for YouTube.
Sharon reveals that the "hero" isn't going to be charged, but the kid that was shot is still facing charges. Choi takes total advantage of the benevolent bigotry from the old woman. Will finds out about the kid at the theater. Connor explains Peter's situation to his parents, and that he only has a day to live without a liver transplant. April and Maggie look at Peter's YouTube channel, and the last one they see shows a camera at the end of his leaf blower. The algebra teacher asks about Peter and expresses disbelief that he's no longer a hero. Charles and Nat check on her patient and the hamburger. She vomits half way through. Nat is appalled to find out that Charles gave her a placebo, and he tells her that she was looking for anorexia so that's all she could see.
Maggie suggests to Charles that he talk to the algebra teacher who shot Peter. He reads off some of the tweets he's been getting, and his frustration that he is now being framed as the villain. Sarah interrupts with the news that his CT results are fine and he's free to go. Charles tries to offer him some sedatives and his card, but the guy refuses offers of help. Outside the hospital, the press gets in his face for a comment. Connor waits outside the door while Sharon talks to Mr. Simms about directed donation for Peter. He's appalled by the request, and refuses. Connor doesn't take the news well. Mr. Simms hands Sharon the signed paperwork as he leaves. Nat notices something with the girl after tests come clear and orders a CT instead. Will updates Choi on Gertrude and then offers to drive Nat to the hospital when she goes into labor. Nat explains the teenager girl's diagnosis to Charles. Mr. Miller is brought back into the ER after stepping in front of a car.
Choi tries to shock Mr. Miller back, but is unsuccessful. Connor brings Mr. Simms to visit Peter and his parents after the operation. He explains that he didn't do it for Peter, but for his wife Lucy. He gets upset and has to be removed from the hospital. Will updates Gertrude on her test results. She has sarcoidosis and Will reveals that she's part African-American. Ethan gently reminds Will that judgment is a tricky thing. The girl insists on the tube over the surgery, and the mother acquiesces. At Molly's, sharon and Charles discuss the events of the day and the impact of social media on society.