Master Wu mistakenly tries to single-handedly complete a battle he began decades ago against Acronix, one of the twin Hands of Time. But the arrival of the first Time Blade-a weapon with the power to speed up time-sends the Ninja to the Monastery just in time to rescue their master from certain doom. Several citizens of Ninjago gather around the doors of the Borg Store, where the release of the latest BorgWatch would be unveiled at.
As the camera pans away from the city, it heads up a mountain, where the ruins of the Monastery of Spinjitzu are. A butterfly lands on a flower before a rabbit begins to eat the flower. Wu then pulls out a watch as a vortex begins to form above the ruins of the monastery. After the rabbit flees, the vortex completely opens and it releases Acronix, one of the Time Twins. As Wu tells Acronix that he's right on time, Acronix is surprised to see how old Wu has become, saying his best days have passed, not unlike his monastery. As Wu tells Acronix that he still has plenty of days left, he asks him that if they should finish what they started, saying that he's been waiting decades. As Acronix remarks that it hasn't felt that long to him, Wu states that it ends now. Meanwhile, at the Ninjago Museum of History, Jay says that it ends now to a statue head of Samukai, though he claims it doesn't help make cleaning up the museum any more interesting. As Lloyd reminds Jay that they are partially responsible for the damage caused to the museum, saying that if it is wasn't for their battles on the Day of the Departed, the place would still be in one piece as he pushes a trolley with a statue of Chen on it.
As Jay questions whose fault that was, Cole apologizes for accidentally unleashing the evil spirits of their enemies onto Ninjago, before throwing the portrait of Yang in a nearby wheelbarrow and is about to move it, but he begins to struggle in trying to control his new hands. Exiting the small room, they meet up with the other Ninja in another exhibit, where Nya puts down a large crate, complaining that if she could travel back in time, she would make it so that she told Dr. As Zane pushes a trolley with a statue of Cryptor on it nearby, he reminds Nya of how some of them have time traveled before, saying it wasn't a joking matter, though Nya tells Zane it's just an expression. As Nya walks over to Kai, he tells her that he doesn't believe it, showing her a painting of their parents. While Nya determines that the painting was made when she was three, Kai explains that they know so little of them, saying they only left them with so little, though Nya reminds him they left them their powers. Cole then gets their attention, where they discover a massive painting depicting Master Wu and Garmadon fighting two unknown men at the Monastery of Spinjitzu while the other Elemental Masters watched. As Cole tells Lloyd that it's his dad in the picture, Lloyd wonders if he'll ever live up to their legacy. As Cole asks if anyone recognizes the battle in the painting, Zane requests P.I.X.A.L. to scan the painting, where she reports that facial recognition tells her that the battle took place forty years ago during the Serpentine War. Cole questions this, saying that Ninjago was at peace during this time, asking who they could've been fighting. As he explains that it is a tea made from pickled beetroot, most of the Ninja spit out their drinks, while Cole drops his, claiming that he was still getting used to his new hands, while Jay drinks it nonetheless. Lloyd asks Saunders what the painting was about, Saunders explains that it was a minor skirmish and that it held no historical significance, saying that was a reason why it isn't hung up in the main gallery. As Jay says it looks significant due to its size, Saunders says that it is all a huge myth. As Zane states that even if it was a myth, he asks who the men Wu and Garmadon were supposed to be fighting, saying he has no data on them. As Saunders puts down his tray on a nearby crate, he explains that there was a legend where two twin brothers known as the Hands of Time, saying they could allegedly control Time itself by speeding it up, slowing it down and whatnot before laughing, saying that time manipulation was a ridiculous fairy tale. As Nya asks who the older one was of the two, Saunders stated that the "handsome looking fella" was called Krux. Lloyd then asks who the nasty looking one was, with Saunders saying that in the stories, he was called Acronix. Back at the monastery, Acronix and Wu circle around the center plant in the courtyard, with Acronix telling Wu to give up, saying his brother wasn't here to bail him out, but Wu tells him that neither is his. Acronix asks whose fault that was, and Wu tells him that he and Garmadon did what they had to do in order to protect Ninjago. Acronix then says he will do he must do before pulling out a dagger and engaging Wu in a fight. Wu manages to knock back Acronix with his staff into a pole and tries to hit him with his again, but Acronix dodges it. Acronix climbs up the pole and as Wu is about to jump towards him, he cuts a piece off of Wu's staff.
Saying that Wu was sprier than he imagined, he asks if he could catch up. Wu then climbs up after Acronix and manages to block Acronix's dagger from hitting him. Meanwhile, at the Temple of Airjitzu, Ronin is carrying a box, asking Misako where he should put it. Telling him anywhere he could find space, she thanks him and Dareth for helping. Though Dareth says he's happy to help, Ronin tells him that he airlifted 300 boxes up to the temple, and Dareth didn't lift a single one. Saying he has a bad back, he tells them that the boxes aren't going to supervise themselves. Misako opens one of the boxes and finds Nya's old Samurai X outfit, which catches the attention of Ronin and Dareth. Saying it came to the wrong place, Dareth tells Ronin to get a look at it. Misako tells them that it was supposed to go to her Samurai X Cave instead of the temple, with Ronin question why, asking that he thought Nya gave up being Samurai X. Misako tells them that she keeps it as a reminder of her "previous life" along with her mech.
Ronin says that if he was Nya, he would've sold it, saying that kind of tech would make some good money.