A car accident that occurs at the Chicago Marathon leaves a victim in critical condition and tests the mettle of Dr. Halstead, April and her fourth-year medical resident brother Noah, who must perform a difficult procedure in the field. A mother brings in her 8-year-old girl experiencing a sudden hearing loss and Dr. Manning is left to tend to the case, which takes a complicated turn. Dr. Choi deals with Olga, a woman who is malnourished, prompting him to bring in Dr. Charles to help assess the case. Meanwhile, Goodwin takes measures to get her personal life in order.

Halstead and Asher clash over a patient in need of a kidney transplant. Marcel faces a tough decision when Blake is in surgery. Choi and Archer treat the son of Med's general counsel. Med's family grows.

Halstead relies on Marcel and Med's newly donated OR 2.0 to save his patient. Charles helps an elderly, confused patient who's mourning the loss of his high school sweetheart. As their wedding day approaches, Choi and April run into some roadblocks.