Willis and Campbell are called out to a Russian submarine that is in American waters. They've have crew injured from an explosion, but are refusing to allow the US Navy access. Willis was specifically requested, and Campbell is part of the cover of them being on a civilian mission. When they get there, the captain is rather brusque, and Ethan finds his old colleague from Afghanistan has also been injured. The captain will only allow them to work on the injured Lt. His main injury is that his clavicle has dislocated backwards, and it's crushing his aorta. They fix that, and then the Russian doctor manages to get the captain to leave sick bay. He then insists that they need more sutures to their patient and sends Willis off to his quarters. On the way, Willis comes across an injured crewman. He brings him back to sickbay as Valkov intended. They've just finished a procedure to save the crewman's kidney when the captain arrives. He's outraged that they've interfered. He threatens Willis, but Ethan points out that he wouldn't shoot an American officer in US waters. The captain agrees and then shoots his sailor in the head. Campbell punches him and a fight breaks out. The first patient comes too and orders everyone to stop. He relieves the captain of duty, identifying himself as a Putin when questioned about his authority.
Prisoners are brought to Angel's after a racially charged riot. Heather bonds with a female guard who stoically hides an injury so that the prisoners won't view her as weak. Her initial wound is easily treated, but one of the instigators of the riot breaks free after a seizure and stabs her in the neck. Because the prisoner is missing, the ER is in lockdown and they can't get the guard to an OR. Heather is the only member of the surgical team available. Despite her best efforts, the guard dies in center stage. Later, Leanne finds the escaped prisoner in her office. He holds her captive with a scalpel to her neck, but she is able to recognize signs that his internal bleeding is getting worse. She waits him out and he collapses after a few minutes. She then calls for a gurney. Heather, still upset about losing the guard, refuses to assist in treating the prisoner despite Leanne's admonishments. They later reconcile, toasting to the guard they lost.
Malaya and Rollie treat a former student of his that ended up in jail after over prescribing painkillers resulted in a patients death. After seeing his CT scans, he realizes that he doesn't have much time to live, and asks to see his wife, who only shows up to get him to sign the divorce papers. The patient quickly recognizes the Rollie's symptoms. The patients wife eventually reconciles with him after hearing him voice his regrets to Malaya. Rollie does not react well when Malaya and Jesse confront him about his illness.
Mario and Angus treat a prisoner who was a victim in the riot. He was shanked twice but only suffered minor injuries. They're surprised when his heart suddenly stops right before they're about to release him. Tests show that he has cardiomyopathy, but he refuses to be put on the UNOS transplant list because he doesn't think that he's worthy. After finding out that he is in prison for murder, Mario agrees. Angus prepares the paperwork anyway, and the man's friend convinces him to agree after reminding him of the letter of forgiveness from the parents of the man he murdered.
Mario's dad's girlfriend shows up to convince him to go to the funeral. He resists, saying he doesn't have a single good memory of his dad. With Angus' support, he decides to go to the funeral. He's surprised when Linda gives him his father's car, and remembers fondly how his dad took him for rides as a kid.