Modo, Master of Mercury, plans his invasion to coincide with a mummer's parade set for December 31, 1952. Along with him is a Jumping Jack from Jupiter, a Stone Man from Saturn, and Thark, a Viper-Ma from Venus. Thark's antennae are used for radio communication, coordinating with Boss Kipley. The alien force plans to rob weapons from the armory while Kipley commits a bank robbery.