A Marine is found dead--face down in the water during a late night training exercise. The military approach Quincy, as they'd like to have an impartial pathologist examine the body. Quincy determines that the guy drowned, but, oddly, the water in the lungs appears to be from the bottom--and the guy never had time to sink to the bottom. No one thinks anything of it--other than Quincy.
As far as the case goes, the Marines are court martialling the man. The accused, the tough drill sergeant, readily takes the blame for it. And, a gung-ho Congressman, looking to grandstand, is anxious to blame the military for this death. No one seems to care that Quincy isn't 100% certain WHAT happened (what else is new?!).
This episode was a bit anti-climactic for me. I predicted the actual cause of death and figured out the chain of events well before the show ended. It reminded me, a bit, of the great war film "The Eagle and the Hawk"--which had a similar sort of ending. Overall, a good episode but far from a great one.