The Ninjago battle the evil ninja robots known as the Nindroids.

The Masters of Spinjitzu have escaped the Overlord and his henchman, Cyrus Borg. But now Sensei Wu is the Overlord's captive, and the ninja are desperate to get him back. There's only one way to stop the Overlord, and that's to wipe out his power at the source -- a system reboot. But the Overlord's minions, the Nindroids, are everywhere, and they are just as skilled as the ninja.