Shaun and Lea's wedding reception is interrupted by a violent attack at the hospital; the trauma of seeing people he cares for in life-threatening situations affects Shaun in more ways than one.

On their first day as surgical attendings, Dr. Murphy and Dr. Park meet the residents they will be overseeing; Lim returns to work while facing her new reality and the emotions surrounding the changes.

The team treats a famous marriage counselor after she injures her ankle; Dr. Audrey Lim is determined to get to the bottom of what really happened in the operating room during her surgery and sets off on her own internal investigation.

The team operates on a military reenactor whose attempt at authenticity has created an explosive predicament; Dr. Jordan Allen and Dr. Daniel Perez are in a race against time as they search for a severed foot.

Shaun, Asher and Powell treat a young patient on Halloween who has a rare hereditary disease, sending them down an uncharted path; Glassman and Shaun must overcome their differences to work together to try and find a solution for Lim's paralysis.

In the midst of a heatwave, Dr. Shaun Murphy and Dr. Danica Powell are at odds when it comes to their patient's surgery; when the hospital loses power, Lea and Dr. Aaron Glassman are forced to come up with a quick solution.

When a woman pregnant with sextuplets arrives at the hospital, Dr. Andrews must split the doctors into teams to ensure their health and safety following their high-risk delivery; Shaun and Lea face their own hurdles as they discuss starting a family.

Drs. Murphy, Wolke and Glassman meet a patient with an infected surgical sponge in their abdomen; Dr. Park must face her past when she treats the victim of a sexual assault.

Dr. Shaun Murphy unknowingly creates a competition between Drs. Danica Powell and Daniel Perez when he introduces a new performance rating system; Dr. Morgan Reznick may have crossed a line with Dr. Alex Park.

Shaun and Lea learn that their surprise pregnancy may come with additional complications; Doctors Park, Reznick and Allen treat a teen with Gardner's syndrome whose past surgical history jeopardizes the outcome of his current one.