During World War One, on April 21, 1918, Germany's greatest fighter pilot - perhaps the best in the world - died as a result of one enemy bullet crashing through his torso while flying his legendary red Fokker Dr 1 triplane, having just been in pursuit of an enemy plane. More than eight decades later the controversy over who fired the fatal shot still exists. This documentary carefully examines the stories of the four most likely to have downed Manfred von Richthofen. Scientific examination of the evidence reveals that, while most accounts credit Canadian pilot A. Roy Brown for the "kill", that is likely not the case. If not, then who is the hero?