It's a beautiful Atlanta morning and Dr. John Ellison, a dedicated ten-year veteran of the ER, is wrapping up a night shift and heading home to his wife Samantha and son Oliver. Unfortunately, before he can get some much-needed sleep the discovery of an injured squirrel sends him rushing to a veterinarian. Along the way, John finds himself in the midst of a much more serious crisis when he hears gunshots ring out near a local playground and realizes a kid has been shot. John runs to assist the boy, and when the shooters return to finish the job, he finds himself left with no choice but to grab a nearby gun and pull the trigger.
After the shooting, John tries to convince everyone that he's fine despite everything that he's been through-a pretence he's had some experience with since the death of his young daughter a year earlier. He returns to work at Samaritan hospital, tending to patients alongside colleagues Bridget O'Neill and Quentin Harper. But unfortunately for John and everyone around him, moving past the shooting won't be as simple as he would like. It turns out the kid he saved, Antoine Tyler, is the son of currently incarcerated gang leader EZ Tyler, and the man John shot was a young member of rival gang, the Nortenos Locos. Now the Locos are coming after Antoine, currently recovering at Samaritan, and EZ is tasking John with keeping Antoine alive and well-or else.
Determined to protect his patient (and his own loved ones) no matter the cost, John enlists the help of unorthodox nurse Gretchen Polk to sneak Antoine out of the hospital to a safer location. But in order to do that, they'll find themselves crossing ethical lines they never thought they'd cross and setting off a dangerous chain of events that could have grave repercussions.
