Sibling blacksmiths Kai and Nya meet a mysterious old man Master Wu, who seeks their help to train under him against the threat of his soon to return brother Garmadon and his new army of Skulkin who dominate the Underworld under leadership of former king Samukai, whom Garmadon overthrew. After Nya is abducted, Kai joins Wu's three other students, Jay, Zane, and Cole to find and protect the Golden Weapons of Spinjitzu. Note: This episode was released in some regions as a 22-minute episode along with "The Golden Weapon". (thetvdb.com)