Atop the mountain where the Celestial Clock continues the countdown towards the final battle between light and darkness, the Overlord appears before Lord Garmadon, noting that he seems conflicted. Garmadon denies this, but the Overlord wonders if he is worried about facing his son, who is growing stronger by the day.
Back at the beach, Dr. Julien repairs the Falcon, while the Ninja celebrate their restored powers by shooting down coconuts. The party is interrupted by Sensei Wu, who chastises the Ninja for their unseemly mirth; they may have the power to defeat the Stone Army, but the Celestial Clock is still counting down to the final battle between light and darkness. At that, Misako reveals a way to at least delay the battle: if the Helmet of Shadows is returned to its pedestal, the countdown might stop long enough for them to gain an advantage.
In Garmadon's camp, the Overlord wonders why some members of the Stone Army are manning vehicles around the perimeter of the camp instead of working on the superweapon. Garmadon explains that he's strengthening their defenses, worrying that the newly-empowered Ninja will attempt to avert the prophesied final battle by attacking him. The Overlord suspects that Garmadon's resolve is wavering, but Garmadon furiously asserts that remaking Ninjago in his own image is his only desire - whether or not he has to destroy his own son is irrelevant. Frustrated by the Overlord's concerns, he angrily orders a nearby group of Stone Soldiers to redouble their efforts on the superweapon - above, the Overlord declares "That's the Garmadon I'm counting on..."
Risking everything, the Ninja disguise themselves as Stone Warriors and escort Misako to Lord Garmadon's camp. As General Kozu takes Misako to his master's tent, the disguised Ninja are put to work carrying Dark Matter to the superweapon. The weapon is surrounded by a wooden wall, but the Ninja notice one protruding detail - a very large cannon - and ponder what Garmadon plans to attack with it.
Meanwhile, Misako appears before Garmadon, who notes that the Stone Army would never be able to catch her - unless she wanted to be caught. Using her husband's lingering affection for her, Misako convinces Garmadon to remove the Helmet, allowing her to steal it. At the same time, the Ninja are discovered when Cole attacks a Stone Soldier, forcing them to fight their way back down to the entrance as Misako rejoins them.
Before the group can flee, an enraged Garmadon stomps onto the scene, piloting a massive, four-armed robot that proves invulnerable to the Ninjas' new elemental powers. Luckily, Nya arrives in the Power Drill just in time, explaining that the repaired Falcon saw that they needed her help. The Ninja make their escape with Misako and Nya, but the Stone Army pursues them until the Overlord reminds Lord Garmadon that the Ninja could turn the army against him if they don the Helmet. Unknown to the villains, Jay has done just that, only to quickly remove it when the others point out that he could be corrupted by the dark headgear.
When the Power Drill emerges in the jungle, Garmadon is quick to pursue. After a frantic chase that ends in the Power Drill being disabled momentarily, Garmadon goes for the kill, only for Lloyd to blast it with his powers. Lord Garmadon emerges from the wreckage, weakened and vulnerable; from the Power Drill, the Ninja encourage Lloyd to finish him off. Despite everything at stake, the Green Ninja is unable to strike the fatal blow, forcing him to jump aboard the Power Drill as the Ninja make their escape from the advancing Stone Army.
At the Celestial Clock, the Ninja meet with Sensei Wu and desperately look for the Helmet's pedestal with minutes to spare. The hunt is interrupted when the Stone Army arrives, but Misako retrieves the helmet when one of the clock's rotating arms knocks it from General Kozu's hand. The Ninja finally find the pedestal and replace the Helmet, but it's one second too late; the countdown has ended and the final battle is upon them. As the clock fires a mighty energy flare inland, the Stone Army captures Nya and the Ninja are sent down into a crevasse. Surviving the fall, the Ninja head off to prepare for the final battle, with Jay angered at Nya's capture and Lloyd ashamed of his hesitation.
Meanwhile, Lord Garmadon sees the laser aimed at his camp, and demands to know what is going on. The Overlord tells him that their superweapon is complete and his to command. The two villains return to the camp as the energy from the clock forms a sphere, completing the ultimate weapon of the forces of darkness: the Garmatron. Lord Garmadon declares that it's more beautiful than even he could imagine, and joins the Overlord in laughing in anticipation of their imminent victory.
The episode title refers to the Ninjas' attempt to return the Helmet of Shadows to its resting place on the Celestial Clock, which is the only way to halt the latter's countdown and delay the final battle.
A running gag in the episode is Jay not knowing the meaning of the word "bequeath." When the Ninja infiltrate Lord Garmadon's camp disguised as Stone Warriors, Jay's attempt at imitating the Stone Army's ancient language is simply saying "Bequeath, bequeath, bequeath!" repeatedly.
Zane saying "tick tock" may be a reference to the episode "Tick Tock," in which he unlocked his True Potential.