After years of peace, Ninja masters Kai, Jay, Zane and Cole are forced to come out of retirement to take on Lloyd Garmadon, the son of their archenemy. When Garmadon releases an army of sinister snake people to help him conquer the land of Ninjago, his evil plan goes awry as he loses control. Soon, Garmadon is himself taken prisoner by the manipulative snakes! In an unlikely twist of fate, Garmadon must join forces with the ninja to stop an enemy that prophecy warns will cast their world into eternal darkness.