Natalie treats a 21 year old college student who comes in with diabetic shock. After resolving his insulin levels, she finds evidence of gallstones which are inflaming his pancreas. After stabilizing his enzyme levels, he starts exhibiting shortness of breath. She does a chest xray and finds pericardial effusion, which is the result of a mass in his lung. The biopsy shows that it is indeed lung cancer. Both he and his father seem overwhelmed by the diagnosis. In order to buy more time for them to come to a decision about treatment, and to allow his pancreatitis to resolve before surgery, she suggests a radiation treatment. While undergoing the treatment, the boy codes. The autopsy shows that he had an extremely rare kind of tumor and that the radiation burst it, flooding his body with toxins. Natalie's day goes from bad to worse when Sharon informs her that the ER Chief, newly returned from a sabbatical/WHO assignment, wants to use the case for the upcoming morbidity and mortality session.
Jeff comes clean about why he and Natalie's husband lost touch -- when his marriage was starting to fall apart, he drunkenly confessed that sometimes he imagined that he was with Nat and Jeff M was with his wife, Linda. Nat is pissed that he kept this from her for so long and gives him the cold shoulder.
Choi treats two MMA fighters who beat the crap out of each other, and tries to keep their brothers from doing the same. Initially he quietly sides with the Arabic fighter who comes in since the other man and his brother make racist remarks repeatedly. When Cyrus falls into a coma, his bedside manner with Ricky the redneck becomes completely cold. He assumes the worst when Ricky appears in the ICU outside of Cyrus' room, and is surprised when Mr. Hammad offers for Ricky to come in and pray with the family, and when Ricky accepts. Inspired by the way Cyrus' father dealt with the situation, he makes amends with Ricky's brother by taking him out for a beer.
As Dr. Charles continues to struggle with the distance between him and his daughter, Sharon asks him to perform an evaluation on a heart transplant candidate who is a recovering alcoholic. Meghan is managing her recovery solo with no support system other than her teenage daughter. Charles doubts her ability to adhere to the post transplant regimen without slipping back into alcohol abuse. Sarah advocates for Meghan, and he reveals that she reminds him of his younger brother who tried to do the same thing and couldn't, and ended up dying. After a chat with his daughter, he reevaluates the case and decides to approved Meghan for the UNOS list, telling Sarah that he hadn't considered the one quality she had that his brother did not -- grit.
April returns to work and has her first sonogram, but the doctor is concerned that the fetus' cranial growth is at the low end of normal. Upon hearing the news, Tate wants to discuss their options going forward, but April refuses to consider termination at all on religious grounds. The disagreement causes tension in their relationship.