There are four new characters introduced: Ethan is an army doc on loan from the DOD. He brings a unique set of skill as well as the latest field tested tech to Angels. He has a generally friendly personality, but is non-apologetic for taking Mike into a situation that he wasn't fully prepared for. He has a sensitive side, exhibited with a young patient. He and Leanne have a lot in common in their attitudes towards medicine, but there are sure to be some bumps along the way as they acclimate to new roles in the ER. There are also three new 1st year residents. Dixon is a young man who seems unprepared for the rigors of the Angels' ER. Noa Kean is a by the book, hesitis Kant to buck authority, and conservative in her diagnoses so as not to be proven wrong. Charlotte Piel is a former child actress (who was the star of a fantasy franchise) who has trouble being taking seriously because of her past. So far, Charlotte is the standout student. She is also more than happy to share credit with others (or give it up entirely) in order to make allies.
Ethan takes Mike with him via helicopter to the site of a shark attack. Mike treats a young girl who has been bitten on the leg and arm and has massive blood loss while Ethan attends to the older boy, who has abdominal wounds. Ethan uses an untested foam to stop the boy's bleeding and stabilize him for transport. They load the patients onto the helicopter, but while Mike is trying to shut the side door, they hit some strong winds and he falls 20 feet onto the beach. When the pilot informs Ethan that he is unable to land, Ethan jumps out of the helicopter into the ocean so that he can help Mike.
Mike ends up in a coma, and Ethan has to drill burr holes in center stage (against Angus' wishes). Angus is reluctant to accept that Ethan saved Mike's life, and blames him for his brother being in the situation in the first place. Their father is dismissive of Angus when he comes to check on Mike, something that Ethan picks up on. Later, Ethan accepts Angus' blame, only for Angus to absolve him. Mike remain in the coma, with no firm date for him to wake up.
The girl who was bit is Kaya, who was at the beach with her older sister, Jayden, and Jayden's boyfriend, whom Kaya has a crush on. She has no compunction about sharing intimate details with Ethan as he treats her, claiming that she had a relationship with the boy too, but that she can't compete with Jayden because she doesn't have boobs. Ethan is uncomfortable with the conversation, and keeps trying to shut it down, with little success. When Jayden arrives at the hospital, she hyperventilates. Kaya cops an attitude with her and they get into an argument. Heather treated the boyfriend, and was confounded by the foam that Ethan used. The first surgery seems to go fine, but later, as Heather does post-op rounds, he starts bleeding again. Jayden finds out that he has died from a news report. She falls apart, but Leanne admonishes her that she needs to stay strong for her sister, and that Kaya can't know. When Kaya wakes up, Jayden still has a hard time keeping it together. At first she doesn't respond to her sister, but when Kaya sees her crying, she figures out the boy is dead, and insists that Jayden leave. Ethan has a chat with her, and she ends up forgiving her sister and they comfort each other.
A man is brought in after being mugged. His son and daughter-in-law-to-be come in...in their wedding garb. The son, Randall, doesn't believe that his father was mugged -- the man has a history of gambling and trouble with loan sharks. He doesn't believe the story until Mama brings him the mans possessions, including a tuxedo and the toast he had written for the wedding. They share a warm fuzzy moment later when the father wakes up.
Savetti assigns Charlotte and Noa to a woman he suspects is merely a drug seeker. Charlotte notices something during her exam, and after noticing crepitus quickly deduces that she has subcutaneous emphysema, likely caused by rough sex too soon after a hysterectomy. Noa is more conservative, and wants Savetti's approval before moving forward with the diagnosis. Savetti didn't notice anything and refuses to sign off on a CT scan. Charlotte is in the process of talking Noa into going along with the scan she ordered when the woman starts to crash. Charlotte takes her into the hyperbaric chamber while Noa runs to get Savetti, who is with Angus, checking in on Mike. Because Charlotte is already in the chamber with the patient, it falls to her to perform the procedure to release the air from beneath the woman's skin.
The hospital (for reasons defying logic) has combined the administration of the ER and the OR, ousting Leanne from the administrative position that she didn't really want, closing the door on Taylor's return, and placing Campbell in charge.
No mention is made of Neal or Christa's absence.