Dr. Shaun Murphy's unique ability to relate to a patient isolated by an immune deficiency yields an unexpected result. Meanwhile, Dr. Claire Browne, Dr. Morgan Reznick and Dr. Marcus Andrews treat a 12-year-old patient who is about to become blind, and tension builds between Dr. Neil Melendez and Dr. Audrey Lim.

Shaun is ready for the next step in his relationship with Carly; however, he continues to struggle as they grow closer and more intimate, and is dealt some troubling news about a deeply personal issue. Meanwhile, a young patient must decide on a treatment that could save her life or possibly destroy her marriage.