27th Day, The

1957

An alien wants to take over the world, yet says he is morally unable to kill the humans who live here. Instead, he transports five humans to his ship and gives them capsules that can kill others with a certain radius, thinking they will all go back and obliterate the world. Some of them commit suicide, some throw them into the river, and the alien decides to let the rest of the world know about the capsules.