Squadron Leader Peter Carter (David Niven) is a British Royal Air Force pilot trying to nurse a badly damaged and burning Lancaster bomber home after a mission in May 1945. His crew has already bailed out, but Carter's parachute has been shot up. He manages to get in touch with June (Kim Hunter), an American radio operator based in England, and talks with her in the few minutes before he is forced to jump without a parachute.
Peter should have died at that time, but does not because of a mistake on the part of Conductor 71 (Marius Goring), the guide sent from the "Other World" to collect him. The thick fog over the English Channel causes him to miss Peter. Instead, the airman wakes up the next day on a beach near June's base, completely bewildered to still be alive.