Ethan transitions to field medicine, despite the reluctance of the EMTs. His new partner, Rox, is impressed with his medical know-how and dedication to patients, but concerned about his disregard for his own -- and therefore her -- safety. During their first foray into the field together, he gets her to break protocol and places them in the middle of a firefight. He uses the ambulance as a shield to retrieve a patient, and rushes into a building after SWAT officers without fully assessing the situation. After that (and seeing him punch a patient's father), she refuses to ride out with him again. But when she sees him apologize to and comfort Elliot at the bar, she reconsiders.
Angus is taken out to the field with Ethan, an experience he doesn't fully appreciate. When they get back to the hospital, he's chosen by Will to head up and assist in the OR. He has a case of nerves in the theater, and Will's brusque teaching method rubs him the wrong way. He consults the surgeon later about how he stays in control, and Will's advice is that you're never in control of life or death, just of your own focus. Later, he's complaining about Will to Mario and Elliot when Will steps out of a bathroom stall, heaving over heard them. Angus is shocked when Will approaches him at the bar to offer him the surgical residency.
Mario and Noa struggle to work out the boundaries of their working relationship now that their dating. Noa repeatedly challenges Mario's diagnosis, and he keeps acquiescing to her desire to run more tests. While they go back and forth about a diagnosis, the patient worsens until Guthrie steps in to place a chest tube. The elder doctor takes them both to task -- who's right about the diagnosis doesn't matter if they don't treat the patient.
There's two new first years at Angels. Pepper has some serious first day jitters and things go from awkward to devastating when she trips and inhales phentanyl that a patient had hidden in their belongings. The other new resident has a father who is a major donor and is thus authorized to make a documentary about Angel's ER...something that annoys a lot of the other docs and sometimes gets in the way of his treating patients.
Ariel has been suspended from school and Leanne has arranged for her to work as a candy striper. She's not overly impressed with her first day on the job, but Jesse encourages her to keep at it with a smile on her face, saying the job is what you make of it. Leanne is worried about her ability to parent a teen, and Jesse gives her the same advice he did when her eldest was born -- the most important thing is to love them.