The vanishing of planes equipped with covert technology across the world leads "Maj. Hammond" (Ralph Richardson) to suspect foul play. His inquiries, often complicated by his journalist sister "Kay" (Valerie Hobson), ultimately succeed in recruiting an up-and-coming pilot named "McVane" (Laurence Olivier) for a scheme designed to expose and apprehend those responsible, despite initial doubts from the aircraft’s produ…