The ninjas venture into the Digiverse to confront the Digital Overlord. Meanwhile, Pythor and Wu lead a Nindroid attack on Borg Tower.

Pythor and the Nindroids free the Digital Overlord. Meanwhile, Wu and Garmadon stumble upon Pythor's top-secret scheme, Project Arcturus.

After battling Nindroids on the outside of the Arcturus ship, the ninjas hang on as the craft takes the battle into the heart of a comet.

The Nindroids use the Golden Weapons to transform the Overlord into the Golden Master. In the ruins of Ninjago, the ninjas prepare their final stand.