In the November 1936 issue of Flying Aces, Donald E. Keyhoe introduced Richard Knight, ace pilot and secret agent of the U.S. government. Along with his dame-chasing assistant Larry Doyle, he confronts evil-doers around  the world, flying his specially equipped (and heavily armed) blue Northrup.

Down upon the flood-lit Washington Airport came a sleek Douglas transport. And from it ran a strangely costumed girl wielding a glittering dagger in spirited attempts to protect herself from the burly men who sought to stop her. Only the lightning decision of a tall, well-built man in a car on the driveway saved her. That man was Richard Knight. And this surprising incident was destined to send him upon the most startling adventure of his career—an adventure which, wholly unknown to him, had begun more than half a century before he was born.

• Download “Vultures of the Lost Valley” (November 1936, Flying Aces)