"how long has he been underwater?" Jay asked nervously
"A long time, he's almost beaten his record" Kai said excitedly
"Shouldn't we get him out?" Jay asked
"he's ok, don't worry" Cole said
After awhile longer Zane surfaces and the ninja all cheer
"have I broken the record?" Zane asked
"more like destroyed it!" Jay shouted excitedly
"We have all made a lot accomplishments these past couple months, I wonder if we've reached our full potential yet" Kai said
"You have only reached your physical peak, your true potential requires mental enlightenment as well" Sensei Wu said as he entered the room to which the ninja whined about
Master Wu begins to relate a story about his childhood, talking about how he and his brother were best of friends. One day while they were practicing their skills, Wu lost his katana, and his older brother sought to find it, knowing their father would not be pleased.
Garmadon found the katana after clambering over the wall, however, he is bitten by a small green snake. In the following days, Garmadon developed an increasingly darker nature, which Master Wu attributes to the snake bite, as it came from "a legendary snake"—the Great Devourer. The tale told, Master Wu declares that he is going on a journey, alone. The Ninja are taken aback, but they and Nya oblige, dropping Wu off at a nearby mountain.
Afterwards, the Ninja decide to go to Jamanakai Village to post signs about the missing Fangblades. As Zane is posting signs, he sees the Falcon. A montage shows the Ninja traversing different terrain to reach the Falcon's destination. During the montage, Jay, Cole and Kai become too tired to go on while Zane proceeds into a frosted forest. As he follows it, the Falcon suddenly drops to the snowy ground.
Zane picks it up and finds it is mechanical. Zane is then disturbed by a robot, though quickly destroys it to find the same symbol on the robot and the Falcon. Zane proceeds into a hollow tree which he discovers is a workshop. While searching through the building, he finds a blueprint with a figure on it and drops to his knees, yelling in disbelief.
Meanwhile, Master Wu enters a tea shop and requests Traveler's Tea. Mistaké, the owner, claims not to have heard of it but upon receiving payment brings out a pot, warning Master Wu that those who drink the tea do not return. Saying that he will not bother her again, he leaves the shop.
Back at the forest, the Ninja find Zane, still on his knees. They question why he is distressed when Zane reveals to them by opening up his torso that he is a robot. The Ninja assure him that although he might not be human he is still their brother, but Zane asks to be left alone after the revelation.
Kai, Jay, and Cole leave the workshop at Zane's request but are soon attacked by Treehorns. They dodge their attacks at first, but are unable to defeat them and are quickly subdued.
In the workshop, Zane takes another look at his blueprints and, realizing he has a Memory switch, flips the switch on. He remembers his father, Dr. Julien, and the different things he taught him over the years.
He remembers the young girl that they found in the woods. He remembered his father explaining to Zane that he was built to protect others, and wishing to save his son the pain of heartbreak, turns off his Memory switch before passing away of old age. Zane, having regained his memories, sheds a tear for his father before rushing out to help his friends.
Together they defeat the Treehorns, but things take a turn for the worse when the Queen arrives. Realizing now who he is, Zane overcomes the obstacles of his heart and reaches his True Potential. Using his newfound powers, Zane freezes the Queen as the other Treehorns retreat. While the other Ninja are happy for Zane for being the first to unlock his True Potential, Zane proclaims with confidence that they are going to find Pythor.