While investigating a heist, the ninja discover Prime Empire, a legendary, unreleased arcade game that suddenly takes control of all other games in Ninjago.

When the ninja connect Jay's disappearance to Prime Empire, they set out to Dyer Island to seek answers from the game's designer, the elusive Milton Dyer.

Cyrus Borg discovers a shocking secret about Prime Empire while the ninja battle an escaped mechanic in their attempt to reach Level 13 and enter the game themselves.

Now inside the Prime Empire game, the ninja find themselves in unfamiliar territory; ignorant of the rules of this world, they try to find Zane and escape Unagami's army of Red Visors.

Inside the game, a samurai named Okino faces a crisis of faith when he repeatedly fails.

In order to stop Unagami, the ninja must obtain three Key-tanas, the first of which is hidden in the game zone Terra Kerana, one of Prime Empire's most dangerous game environments.