When the preying mantis-like moon insects begin to attack Lunar Station X-32, the Space Rangers discover a plot by Halgo, leader of the Outerplanetary Circle, is waking up the underground creatures. Halgo plans to steal destructive mirrors, old Earth weapons buried on the moon.; The Space Rangers track down Nucleo, a shape-shifting Martian. He takes the figure of Captain Arax, and thusly his leisure cruise spaceship, the Staritania.; Boss Kipley and his cohort Pete intercept alien radio signals. Boss Kipley arranges to have Modo, Master of Mercury, land with his invasion force of aliens. The arrangement was for December 31, 1952, when a Mummer's Parade was going on. Modo is a mud man from Mercury. With his invasion force, Modo brings Thark, a Venusian Viper-Man, one of the Jupiter Jumping Jacks, and a Stone Man from Saturn. The police dismiss radio transmissions received until one concerning a Kipley's bank robbery and Modo's aliens heading toward the armory. The police handle both situations.; With the assistance of Professor Eon Tempus, Hap Holliday, Time Skipper, designs and builds his "Year in an Instant" yacht, In their first outing, the pair visit the year 100,001. The encounter a dry seabed with giant crab-like creatures and a giant, land-traversing octopus. shooting the octopus with his rifle, Hop rescues Ula, Queen of Futuropolis. Futuropolis has been overtaken by the reptile-people, who drove the people out. Hap returns to the day of Ula's banishment to set things aright.