A young pilot fresh out of training is called to join a flight while they wait for the call to scramble. Throughout a single day, the skies of southern England are filled with deadly dogfights, and after every exhausting battle, the pilots return to the dispersal hut only to find another of their number missing. In a thrilling climax, the airfield comes under direct attack and the flight takes off, once again, ascending into action against fatally overwhelming odds.