A E van Vogt & E Mayne Hull's "The Flight That Failed" aka "Rebirth: Earth" (as by E M Hull) (short story, weird, free): Making a future happen where Germany loses in WWII
Story summary.Pilot of secret flight of a US military plane carrying some extremely valuable, but unspecified, cargo & some military, technical & diplomatic personnel, to London during WWII discovers a stowaway, presumed a German spy.
All attempts to arrest & confine him fail in a bizarre way. He claims to be an illusion, projected there by a "moon ray time reflector machine" from an alternate future in which Germany is defeated in this war. And nobody believes him when he tells them the success of this flight is crucial to the future where US wins, & this flight is doomed unless they let the stranger man one of the machine guns of the plane in a German attack to come in a few minutes...
Fact sheet.First published: Astounding, December 1942.
Download full text as part of the scans of the magazine it originally appeared in.
Among the stories from Astounding/Analog issues edited by John Campbell.
Related: Stories of A E van Vogt.