When a U.S. marine or sailor is wounded in combat, his odds of getting to a doctor are close to nothing. But his chances of staying alive are superb due to the Navy Hospital Corpsmen. They aren't doctors, but their job is to be at the center of battle, lightly armed and carrying no more medical supplies than can be dragged in a shoulder bag. In dynamic interviews with veterans and brand new footage, we see how, while performing their duty over two centuries, many died, willingly, in shocking numbers.