A fireworks explosion creates chaos at a concert, sending patients streaming into the hospital as TC and Topher race to the scene. Also, Syd returns from Afghanistan and faces her unique family dynamic; Jordan and Scott address simmering differences.

When a bomb explodes outside the hospital, TC, Topher and Drew are forced to make the tough decision to stay and treat the injured or evacuate and begin transfers to nearby hospitals. Everything changes when TC suddenly realizes he may know the person responsible for the explosion. While the team works feverishly to tend to the wounded, the nurses go on strike just when the hospital needs them the most. Meanwhile, throughout the intense night shift, Shannon and Paul attempt to confront each other about something personal.