An archeologist wills himself back into the past, discovers that a race of intelligent good-humored "mutant giants" coexisted with Pithecanthropus erectus, and sets in motion a chain of events which wipes out the race of giants.; A sea captain in love with the sea is saved by the sea after it wrecks his vessel.; A man invents a rocket capable of making the trip to Mars and a Martian lawyer buys the patent so that they will not be receiving any unwelcome visitors.; A story told from the point of view of a robot who is kept under guard while scientists use him to answer calculations bearing on questions of national security.; An alien gets the idea of installing flying saucer rides in amusement parks as a way of calming fears about flying saucers.