The Ninja travel to the Village of Stiix to find the thief who stole the scroll of Airjitzu, but the self-serving Ronan isn't keen to sell it cheaply so the Ninja must figure out a way to make money on the docks – and when they fail to make enough cash, the Ninja decide to steal it – but have a run in with Moro and Sowlarcha.

Lloyd moves in and tries to make nice by helping out with chores, but he just gets in the way. Pythor has awoken the Vipoids and the Constrictaurs and an all out snake war has taken over Ninjago. The Ninja are not faring well, when a mysterious Samurai shows up and saves the day.

Kai promises to watch over Lloyd when Lloyd fears the loss of his father will make the path ahead uncertain– but when Wu sends them out on an errand for his new Tea Farm, Lloyd goes on a solo mission... only to discover it's a trap from a GHOST who's escaped the Cursed Realm.

Disaster threatens as the ninja must fight to defeat the all consuming Great Devourer in a desperate attempt to save Ninjago.

Back in training mode with the looming threat of Lloyd and the Hypnobrai, Zane wanders after a Falcon and lands himself in a heap of trouble. The rest of the Ninja leave the training dojo to help him and return to find that the snakes have burned it to the ground.

When Garmadon uses his new Super-Weapon to turn Jamakai Village evil, he unwittingly unsettles the balance, allowing the spirit of the Overlord to cross over and possesses his body.

When Moro uses the Realm Crystal to open a portal to the Cursed Realm, ghosts take over the town - but the Ninja, in disguise, manage to get Lloyd to the center of the town and Lloyd steals the crystal…only to discover it's too late as the Preeminent arrives.

The Ninja and fighters discover there's a strategic location called The Corridor of Elders where they can make their last stand against Chen's Anacondrai army... but even with the new Destiny Bounty, their forces still aren't strong enough. Fortunately, Pythor escapes Chen's clutches and discovers there is one spell in the Book of Magic that could stop the war, but at a serious cost.

The Ninja hear of another way to learn Airjitzu - from the ghost of Sensei Yang at his haunted temple - but there's a warning; if you are trapped in it by sunrise, you will become a ghost, too. Meanwhile, doubting she's a Water Ninja, Nya quits her training to take Ronan to her Samurai X cave…but has a run in with Moro.

The Ninja now have all the items they need to get to the tomb of the First Spinjitzu Master but before they can figure out the last riddle that leads to the location of the tomb, Ronan steals the sword to give to Moro in exchange for his soul, and the Ninja and Nya are unable to stop him.