Commander Dumax and his army of praying manti (who look exactly like Space Ghost's sidekick Zorak) have come to invade Earth. The Neptune's, on their way to Hydrostan, hear of a UFO sighting in the area ,and Biff decides to use this as a publicity stunt. Unfortunately, Clamhead and Jabberjaw are pursued by the aliens, the stunt backfires. In the meantime, Dumax gets an Earth identification device, which will help with his plans. The Neptune's are taken prisoner by Dumax but escape and must thwart his invasion plans.