Mystery in Space #10

A group of humans on a train are transported across the universe to Almoran. At the same time a group of Almoran aliens are sent to Earth disguised as Earthlings. The humans and Almorans are flashed by a ray from an enemy spaceship causing the Almorans to fall asleep. The humans pretend to be asleep and then defeat the attackers. The Almorans reward the Earth people by allowing them to keep their memories of the adventure but place a mental block on them to prevent them from talking about it.