When a colossal spacecraft erupts from the moon and an alien energy pulse cripples Earth's defenses, Professor T. Bird realizes the Dark Queen has returned from her exile in deep space with a vengeance. This time, however, the vengeful tyrant has made a calculated alliance with the Shadow Boss, assembling a formidable coalition that includes General Slaughter, Big Blag, Robo Manus, Abobo, and Roper. The Battletoads—Zitz, Rash, and Pimple—face their most dangerous challenge yet, prompting the Professor to call in reinforcements: the legendary Double Dragon fighters Billy and Jimmy Lee, whose personal vendetta against the Shadow Boss makes them natural allies in the fight to save the planet. With Earth's fate hanging in the balance and enemies converging from multiple fronts, the unlikely team must combine their martial prowess to stop the Dark Queen's latest scheme for galactic conquest.