Adam's competing in a karate tournament against Shawn, Tanya's ex-boyfriend, who's got a new gal in the form of snobby Veronica. Shawn discovers an invisibility device left over from the Machine Empire's latest scheme, and plans to use it to cheat against Adam in the contest. Meanwhile, the Rangers face Admiral Abominator, who's preparing a fleet of battleships in Angel Grove forest. As a result, a number of trees begin disappearing, which Bulk & Skull are assigned to investigate.