Amanda takes her boyfriend's son to a haunted house, but while they are there, a fire breaks out and the little boy is caught. While the ER deals with a flood of (costumed) patients from the disaster, Ethan heads to the site with Noa and Elliot, who he promptly leaves on their own. They work to stabilize the actress hired to play the murderess, but Elliott misplaces the central line. They manage to stabilize her and get her to Angels. Meanwhile, when Ethan reaches Amanda, the boy is trapped in the projection room with a major laceration to his leg. It looks like he's possibly damaged the femoral artery. They facetime with him, and Ethan talks him through making a tourniquet for himself. It's only at that point that he reveals that he's also been hurt in his abdomen. He shows his bruise to the doctors, and Ethan determines that he's bleeding internally. He calls Leanne to make sure that a specialized piece of equipment (a REBOA) is sent to the site so that he can use it as soon as the kid is free. During their time together at the theatre, Ethan reveals what he did to get sent to Angels. While they wait for the rescue team, the building shifts, and Amanda is injured as well. The shift allows Ethan to pry open the door and get the boy out. They are eventually rescued by the EMTs, and Ethan successfully performs the delicate procedure in the back of the ambulance. They arrive to find the ER in chaos, and no surgeons available. Ethan co-opts an initially reluctant Heather to help him save the kid's life. Later, she is shocked when Campbell reinstates her privileges, telling her that he can respect when her disobedience is to save a patient.
The reason that Ethan got sent stateside to the program at Angels is that he disobeyed orders by traveling to as many villages in Afghanistan and providing medical care to anybody who asked after being ordered not to. Before that, he had traveled to a village to perform an emergency appendectomy on a young boy, but a few days later, the Taliban forces left the child dead in the middle of the road, with a bullet through his head and his sutures ripped out.
A little girl crashes a car into the ER drive, alerting the doctors to her grandfather's heart attack. When the mother arrives, she blames the situation on the older brother, who was supposed to take the girl trick or treating but bailed to go to a party. When the old man codes in the cath lab, the doctors are unable to resuscitate him. The boy blames himself and is worried his mother with hate him. Leanne shows him his grandfather's scans, and insists that he was a ticking time bomb. When they leave the diagnostic room, the mother assures her son that it is not is fault and that Grandpa lived a good life.
Attempting to comply with Campbell's orders about Charlotte, and to best manage patient intake, Leanne sends the young doctor to handle intake in the waiting room. When a paranoid addict wakes up in the ER and is confused and scared by all the people in costume, he struggles with a security guard and manages to get ahold of a gun. After he fires a few shots, Campbell tackles him. At first it seems that a little girl dressed up as Jessamine has been shot, but it turns out that Charlotte shielded her and took the bullet. The team fights to save her, but is unsuccessful. Jesse reassures Leanne that Charlotte's death is not her fault, but she has a hard time accepting it.
Campbell and Leighton pere want to perform a trachisotomy on Mike, but Angus is against the procedure. He favors extubation based on recent intentional movements from Mike. Angus waivers back and forth on his decision, with his father trying to guilt him into going along with Campbell and Mario telling him to trust his instinct. In the end, he performs the extubation, and after a stressful minute, Mike breathes on his own.