Peter Fortymore can't believe his brother is dead. So he conceives a desperate plan. He'll run away from school, 'borrow' a plane and fly off to France to find him. In the chaos of the first world war, he and his friend manage to get away with it until they're rumbled by their flight commander Biggles.
'We shall have to wait until they come out,' breathed Biggles. 'Jump out when I do and be ready to shoot like lightning. If they drop their rifles and put their hands up, all right, but any move by one of the to raise his rifle, let him have it. It's the only way. It's either they or we for it, and they won't hesitate to shoot us. Ssh! Here they come.'A sixteen-year-old boy learns that his beloved elder brother has gone missing from his squadron and decides to rescue him. With his friend, he runs away from school and they sign up in the RFC, lying about their age. They meet up with Biggles at 266 Squadron and join his flight - but will Biggles find them out?