Action Comics #368

THE UNEMPLOYED SUPERMAN! / SUPERGIRL'S STAND TO SAVE STANHOPE! Returning from a trip to space, Superman is puzzled to learn that there is no more crime on Earth, and natural disasters have ceased also. Space beings called the Sentinels claim responsibility and convince him to leave Earth, where he is no longer needed. Supergirl defeats future criminals Alpha and Beta and their plot to change history; Law enforcement officials from the future reveal that they prevented Supergirl from exposing herself to Gold Kryptonite.