A corrupt police chief uses frivolous fines to fund a giant useless prison in order to increase his own prestige. He imprisons a passerby for no reason, but is shocked to find that he is the leader of a group of aliens who are in such a rush to leave that they take the whole prison when they cannot open his cell, leaving the chief disgraced and humbled.; A researcher receives telepathic signals from evil Martians, now long dead, who want him to build a machine that will allow them to cross space and conquer Earth. The gold that he gets through the machine as payment is now molten and buries him.; A robot is given a command to kill the man in the room by someone who wishes to steal the robot after it has slain its creator. When the would-be thief enters the room, the robot slays him as well, then the robot goes out into the night looking for rooms to slay men in.; Aliens from a dry desert world park their invasion fleet on a large expanse of the ocean thinking it to be a solid surface, whereupon the ships sink like stones.