Shaun and Lea's long-awaited wedding reception is interrupted by a violent attack at the hospital and the entire team must mobilize to save the victims. Meanwhile, the trauma of seeing people he cares for in life-threatening situations is affecting Shaun in more ways than one.

The team treats a famous marriage counselor after she injures her ankle from falling, but when she offers relationship advice to them, Dr. Morgan Reznick quickly spots that their patient might be experiencing something far more serious. Meanwhile, Dr. Audrey Lim is determined to get to the bottom of what really happened in the OR during her surgery and sets off on her own internal investigation.