Peace has returned to Ninjago, and the Ninja have grown complacent. Rumours of Lord Garmadon's return prompt them to investigate, but they only find his son, Lloyd Montgomery Garmadon, causing mischief. Driven by a desire to become like his father, Lloyd fortuitously uncovers the Tomb of the Hypnobrai Tribe of the Serpentine and releases them. The Ninja come across the prophecy of the legendary ‘’Green Ninja’’ and, believing one of them is destined to become him, begin fighting amongst themselves, while the Serpentine attack Jamanakai Village.