Since Lord Garmadon’s disappearance from the Underworld, NINJAGO Island has been at peace, but the young ninja have grown lazy. While Garmadon lurks in the shadows, waiting for the right moment to strike, the ninja meet his young son, Lloyd, who carelessly unleashes a fearsome new enemy upon NINJAGO Island – the ancient tribes of the Serpentine. The leader of the Serpentine, Pythor, hatches an evil plan to bring back the legendary, all-consuming snake, the Great Devourer.