Dr. Murphy treats a patient who has an illness that is not only unpredictable in nature, but also unlike anything he or the team has seen before. Dr. Claire Brown continues to work through her grief, still reeling from Dr. Neil Melendez's death.

Shaun has a hard time balancing his fears and concerns about potentially jeopardizing Lea's health and wanting to be with the woman he loves. Claire looks for a way to grieve Melendez's death. Park and Mia discuss their future together.