Wrong Place, Wrong Time

"Why does time travel have to be so complicated?" - Kai

Wrong Place, Wrong Time is the sixth episode in the second season of Ninjago: Masters of Spinjitzu.

Plot
Aboard Destiny's Bounty, the Ninja train Lloyd with a variety of weapons and skills. Nya comments that Lloyd has become a fast learner now that he's aged, but Sensei Wu tells his pupils to challenge Lloyd again, this time at full strength.

Later, the Falcon arrives on the Bounty and shows the Serpentine back in the City of Ouroboros, apparently preparing for a final battle. The Ninja head to the city and arrive at night. While Fang-Suei works on the Fangpyre truck, Sensei Wu and the Ninja confront Lord Garmadon, only for Lloyd to arrive and freeze the tip of the Mega Weapon. Garmadon is surprised to see his son as a young man, and Lloyd explains that things have changed since they last met.

While Fang-Suei, Chokun, and Mezmo battle the heroes with their power tools, Lord Garmadon flees to a nearby building. As he tries to break the ice off of the Mega Weapon, he laments the Ninja's continued interference, wishing that they never existed. This statement inspires him to create a time portal and step through it. The Ninja find the portal as sand begins to rise, which Zane identifies as the City of Ouroboros returning to the desert, as if it had never been found in the first place. The heroes realize that Garmadon is manipulating the past, preventing the Ninja from ever forming and training Lloyd - sure enough, the Green Ninja comments that he can no longer feel his hands. The Ninja decide that they have to follow Garmadon into the past, with Sensei Wu warning them that "if he changes anything, he changes everything".

The four Ninja jump into the portal and land in a muddy rice field, not far from Four Weapons in Ignacia. They realize that they have returned just as Sensei Wu's past self was attempting to recruit Kai for his academy (as seen in "Way of the Ninja"). At first, Kai wants to warn Past Kai and Nya about the Skulkin, but Zane explains that any changes to the past will affect the future dramatically. After Past Sensei Wu leaves the shop, the four Ninja ambush him and explain their situation - realizing too late that they have inadvertently changed the past in the process. Despite this, Kai persists in asking Past Sensei Wu for his aid. Although confused by the events, Sensei Wu agrees to help.

Moments later, the Skulkin burst onto the scene, with Garmadon disguised as a Skulkin manning the Skull Truck. While the present Ninja watch, a group of Skulkin sneak behind them, but Jay defeats them with ease. After Kai warns Past Sensei Wu about the impending events and his role in them, all goes as before until Samukai commands Kruncha to kidnap Nya. Instead, Garmadon forces his way past Kruncha and intentionally fires the truck's bone hand to miss Nya. The Skulkin retreat, but not before a confused Nuckal sees the two Kais, although he ignores it. In the present, a wave of dark clouds looms over Ninjago City, and a picture of Lloyd from a portrait disappears, indicating that he is no longer with the Ninja in the present.

Back in the past, Kai realizes that he misinterpreted Garmadon's plan - by preventing the Skulkin from kidnapping Nya, he has removed Past Kai's reasons for becoming a Ninja. As Zane explains to Jay, if Kai never becomes a ninja, all of their actions in the future will be undone; the four of them will never become a team, Lloyd will never be trained to become the Green Ninja, and Nya will never fall for Jay. At this last fact, Jay desperately tells Past Sensei Wu to recruit Past Kai no matter what - although Past Kai is reluctant, Nya encourages him to go, thinking that it could be a fun experience.

The present Ninja soon find themselves at the Monastery of Spinjitzu, watching Past Nya and Past Kai training. However, Past Kai is barely interested in training - the present Ninja realize that Kai's only motivation to train well was Nya's kidnapping at the hands of the Skulkin. Consequently, Zane resolves that they must kidnap Nya and hand her over to the Skeleton Army to motivate Past Kai and set events back on track. That night, Zane, Cole, and Jay disguise themselves as Skulkin and kidnap Nya - meanwhile, Kai acts as Past Kai's reflection in the bathroom mirror, then tells Past Kai he should start listening to Sensei. Meanwhile, as Jay, Cole, and Zane take Nya in a sack, the other three Past Ninja, wearing their black suits, spot the three present Ninja. As the three Ninja fight their past selves, Past Kai hears Nya's cry for help, forcing Kai to knock him unconscious. With their ally in the outdoors battle, the present Ninja get away with Nya; in the present, Lloyd's portrait is restored.

In the Forest of Tranquility, the four Ninja find the Skulkin camp and drop off Nya in front of Kruncha. However, Lord Garmadon has realized that his foes are interfering with his plans, prompting him to appear before his past self in the Underworld. Although Past Garmadon is highly confused by the appearance of his future self (especially the fact that he has four arms), Garmadon quickly explains the circumstances and formulates a new plan with his past self. In the present, the dark cloud reappears over Ninjago City, larger than ever, and Lloyd's portrait disappears again.

Back at the forest, the present Ninja and Past Sensei Wu are watching the past ninja sleeping around a campfire. Jay wonders why they haven't returned to the present, and Cole reminds him that they still have to make sure that the rest of the events play out as before. As Kai explains the significance of these events to Past Sensei Wu, Past Kai is lured to the Fire Temple by Nya - which Kai explains is a trick by Lord Garmadon in order to eventually unleash a great evil.

The present Ninja and Past Sensei Wu follow Past Kai to the temple, where they watch Past Kai claim the Sword of Fire and use his Spinjitzu to save Nya. However, Kai realizes something is wrong when Past Garmadon responds to Past Kai's taunts differently than he remembered. Suddenly, Past Kai is attacked - not by his own shadows, but by the present version of Lord Garmadon.

Realizing that his past self doesn't stand a chance against the four-armed Garmadon and his Mega Weapon, Kai grabs the Sword of Fire when Present Garmadon knocks it from Past Kai's hands and leaps into the fray himself. Cole and Zane join in, but even three present Ninja are unable to defeat Present Garmadon. As the dark warlord celebrates with his past self, Zane comes up with an idea: by destroying the Mega Weapon, they might be able to undo all of the changes to the present. Although Kai agrees (despite Zane admitting that it's only theoretical), Cole points out that the only way to destroy the Mega Weapon is to use something of equal power - and no weapon can equal the power of the Mega Weapon.

At this, Jay disagrees; he brought the other Golden Weapons for the present Ninja to use. With their ultimate weapons in hand, the present Ninja combine their elemental powers and blast the Mega Weapon, while Past Sensei Wu uses his own powers to pull it out of Present Garmadon's hands. As everyone looks on, the Golden Weapons are pulled from the Ninja's hands and combine with the Mega Weapon, hurling it into space before it explodes brilliantly. Nya vanishes into thin air, Past Kai demands to know what's going on, the entire volcano begins to crumble as it is engulfed in light...

...and the Ninja find themselves back in the training room of the Destiny's Bounty. For a moment, they fear that Lloyd is no more, but Lloyd quickly rushes into the room, apologizing for being late. The Ninja embrace their comrade, thankful that the timestream is back in order - however, Lloyd is confused by their talk of Lord Garmadon's Mega Weapon; apparently, by destroying it in the past, it was erased from the future.

As the perplexed Lloyd uses a sword to carve a slice of watermelon into a dragon sculpture, Kai tells him not to worry about it - some things are best left in the past, so they can focus on preparing for the future. Meanwhile, Sensei Wu is looking at what is presumably the remains of the Mega Weapon, a distant bright star in the sky.

Trivia

 * The episode title is a reference to a series of common sayings about the proper time and place for actions or objects, such as "wrong place, right time" and "right place, wrong time". It could also refer to Lord Garmadon's plan in the episode; by making small changes to past events, he produces different outcomes that lead to the future changing in his favor.
 * The final version of the series' title sequence makes its first appearance in this episode, featuring Lloyd's new teenaged form.
 * This is the first appearance of Samukai since "Weapons of Destiny".
 * The Ninja and Lord Garmadon use Skulkin masks to disguise themselves from the people of the past. Strangely, no one sees through the disguise, similar to how Lloyd fooled the Serpentine with a crude Rattla disguise in "The Snake King".
 * According to "An Underworldly Takeover", Garmadon's helmet was taken from Samukai. However, none of the Skulkin appear to notice one of their number wearing Samukai's helmet.
 * The shadow form of Lord Garmadon's past self has changed slightly from its appearance in the pilot, being less translucent and having his present form's helmet design.Garmadon_shadow_differences.png" (left) and "Wrong Place, Wrong Time" (right)]]
 * Sensei's Wu's line, "Great Scott!" during Lloyd's second present disappearance is a reference to the movie, Back to the Future.
 * The way the Ninja destroy the Mega Weapon hearkens back to the invoking of the Tornado of Creation, although the order of the elements is different and Sensei Wu provides the cry of "Ninja, go!"
 * The climax of the episode - using the Golden Weapons of the past to destroy the Mega Weapon - could potentially lead to a temporal paradox, depending on whether or not the Golden Weapons of the past were restored by the time stream repairing itself:
 * If the Golden Weapons were not restored, the rest of the past events are severely derailed - among other things, Samukai would not have been destroyed, Lord Garmadon would not have escaped to his dark dimension, and the Ninja would not have gained their vehicles, thereby greatly limiting their transportation options after their dragons leave to molt.
 * On the other hand, if the Golden Weapons of the past were restored, events could play out as before until the aftermath of the battle against the Great Devourer. Lord Garmadon would still have the Golden Weapons, but apparently did not create the Mega Weapon with them (as it appears to have been erased from the present). In this case, it would appear that Garmadon lost the Golden Weapons at some point instead (possibly, the Golden Weapons were simply destroyed at the Golden Peaks instead of merging into the Mega Weapon).

Errors

 * Since the Mega Weapon was destroyed, the ninja would have never turned to children, causing Lloyd not to grow up, yet he was still the same age as he was after Child's Play.