Astounding Stories #36

In "He Wore a Black Beard," a man living with an inventor is thrown off balance when a visitor claims to be from the future. As tensions rise, he hatches a plan to frame the inventor with the visitor’s help—only to realize too late that the time traveler is the inventor’s own future self, and the man’s scheme is a loop he can’t escape.

In "It Waits Under the Sea!" from Astounding Stories #36 (1968), a lone diver ventures into the deep with a daring global journey in mind—only to be lured by a mysterious underwater tunnel. Drawn in by the unknown, he finds himself trapped in a hidden holding tank, sealed away beneath the sea until the next time the exhibit is opened.

In "The Replacement!", a desperate criminal steals a dying man’s jacket and discovers an airline ticket inside—only to find himself aboard a plane with no crew and no other passengers. As the aircraft lifts off into the unknown, his panic grows with every empty seat and silent cockpit. When the police later find his body in a field, the man he stole from is miraculously alive, having escaped death by chance.