Major Robert Lee Scott Jr. [Dennis Morgan] is a 34-year-old Army Air Force pilot who is considered too old for frontline combat, yet he is recruited to fly a secret bombing mission from the Philippines against Tokyo, the Japanese capital. When the mission is cancelled after his arrival in India due to the fall of the Philippines, Scott is promoted to Colonel and assigned to fly transport aircraft on dangerous, unescorted missions over The Hump from Burma to China. These flights supply aviation gasoline and other crucial supplies to the three squadrons of the American Volunteer Group, the Flying Tigers.
Over time, Scott persuades Maj. Gen. Claire L. Chennault [Raymond Massey], the Tigers’ commander, to let him fly with his seasoned airmen, such as Tex Hill, who have been fighting the Japanese as mercenaries while officially serving with the Chinese Air Force. Scott gets his chance to finally fly one of their Curtiss P-40B/C Tomahawks, engaging in aerial combat missions and becoming a double-ace while flying with the AVG.
On Independence Day, the 4th of July, during a surprise bombing and fighter raid on Japanese-occupied Hong Kong, Scott duels with the infamous Japanese fighter ace nicknamed “Tokyo Joe” Tokyo Joe. Although Scott’s engine is hit and losing power, he suddenly drops his landing flaps, which quickly reduces his airspeed. Joe flies past and Scott sights him in his cross-hairs, firing nearly point blank at the Zero with his six .50 caliber machine-guns, setting Joe’s fighter aflame. Scott says in triumph over his radio, > There’s your six-feet of China, Joe, now go fill it up. < The burning Zero fighter spins out of control and crashes, as Scott’s damaged P-40 continues to smoke and lose altitude. When Scott does not return to base, and no further word of him is heard after several days, he is presumed killed in combat. As Chennault begins to write a letter to Scott’s widow, he hears a growing commotion outside. A nighttime, torch-lit, gong-playing Chinese procession enters the Tigers’ compound, carrying the injured Scott, who is bearing Tokyo Joe’s Samurai sword.
After a physical examination, despite Scott’s assurances that he is fine, the doctor grounds him due to his age, combat fatigue, and recurring malaria. He has to sit out the largest air-raid against the Japanese ever planned in China. As Scott listens through an open window to the mission briefing, Chennault arrives at a personal command decision. He tells Scott that a new, larger P-40 fighter, with a more powerful engine and additional firepower, is his to fly for one final mission, a gift from “the old man.” Elated, Scott goes to the plane, fires up the engine, and rapidly gets airborne. He quickly climbs skyward to join the squadrons of fighters and bombers formed-up and heading east toward certain victory.
