While Kai was brushing his teeth, three mysterious ninja began to attack him. After a short battle, he was thrown onto the training course, Sensei Wu soon entered the scene and revealed that they were his students. He performed Spinjitzu, giving them each differently colored ninja suits to represent their elements: Cole, the Black Ninja of Earth, who has a fear of dragons; Jay, the Blue Ninja of Lightning, a talkative inventor; Zane, the White Ninja of Ice, who doesn't have a sense of humor; and Kai, the Red Ninja of Fire. Jay became interested in the mission when he learned about Nya, though he was warned by Kai to back off.
The next morning, they traveled to the Caves of Despair to find the Scythe of Quakes, pulling a horse carriage with Wu inside of it. Along the way, Kai questioned how the others were found by Sensei Wu. Cole stated that he was testing his strength by rock-climbing up a mountain, Jay says he was in Ninjago City testing his homemade wings and Zane says he was testing himself by breathing underwater at an ice-cold temperature; in all those scenarios, Sensei Wu was there, drinking tea.
Arriving at the Caves, Sensei Wu warned the ninja not to use the Scythe upon retrieval, fearing they would not be able to handle its power. After stealing back the map that contained the locations of the Golden Weapons, they entered the cave and found the Scythe. Upon leaving, however, they were ambushed by Samukai and his Skeleton army. While fighting the Skulkin, Jay mentioned that fighting them felt like the training course back at the Monastery, and in going through the motions, Jay unlocked his Spinjitzu. Not long after, the other three ninja unlocked theirs as well.
The ninja defeated the Skulkin easily but were soon faced with the Guardian of the Scythe, the Earth Dragon. As they were unable to defeat it themselves, Kai used the Scythe, despite the warnings of his teammates and defeated the Earth Dragon; the ninja barely managed to escape. Outside, Sensei Wu was sorely disappointed in Kai and scolded him for putting the others in danger.
In the Underworld, Samukai informed Garmadon that he had failed: The ninja had unlocked Spinjitzu and the Scythe was now in his brother's possession. Garmadon takes this news lightly.
When the three ninja come into Kai's room at the monastery, Cole has Zane's eyebrows.
A while later Zane is then shown with Cole's eyebrows
Jay, Zane, and Cole's have their weapons out when they sneak up on Kai, however after Kai says "Whoops!" their weapons are no longer in their hands, but rather on their backs.
While Kai and Cole are rolling on the ground during their fight, Cole is wearing his Earth Ninja gi as opposed to his original plain one.
During Wu's talk with the ninja, his teapot continuously changes places in the background of the scene.
When the ninja ready themselves to fight the Skulkin army, in the next three camera changes Samukai can be seen standing in the same position when he stopped the ninja, however, in the next camera change he disappears.
Cole claims he warned Kai not to use the Scythe of Quakes, even though it was Jay who warned him. What's even more weird is that Kai's mouth appears to be moving instead Cole's.