Hours have past, and Princess Celestia and her friends have been looking for her sister, who has disappeared from the castle. Now that it is nighttime, Princess Celestia worries that Princess Luna will transform into Nightmare Moon before they can find her.

"This is bad…" Princess Celestia said to her friends, as they knew that they had to find Princess Luna before things can get worse. "If we don't find my sister, then we'll all be in trouble.

"I agree." Applejack agreed, as she was stepping in so that she and the others could help Princess Celestia find her sister.

"But… are you sure this will work?" Fluttershy asked, believing that they might not rescue Princess Luna on time. "What if we can't find her as fast as possible?" She added. "Oh, shush, Fluttershy." Rainbow Dash told her, putting her hoof around Flutttershy's neck. "I'm sure that we will catch Princess Luna before she transforms into Nightmare Moon!"

Pinkie Pie, looking at her hooves, laughed and said, "It's time to step it up or notch because we gotta capture one princess tonight!"

The Mane Six and Princess Celestia ran out of the castle and search for Princess Luna. Meanwhile, Princess Luna, who had got into an argument with her sister, was hiding somewhere, preparing to transform into Nightmare Moon before the others could even find her.

"Hm hm hm hm hm…" Princess Luna laughed in a crazy way. "Once I transform into my dark side, they will realize that I'll be more powerful than before!" She said, as she started looking at the moon.

"Arise, moon!" Princess Luna said using her traditional Canterlot voice, as she began to fly up to the moon, preparing to unleash her dark side out.

Back with the others, they were still searching for Princess Luna, in which they might not make it in time. "Does anypony see Princess Luna?" Rarity asked her friends, looking for answers. "Nope." Twilight Sparkle and Rainbow Dash answered back.

"We can't let my sister disappear." Princess Celestia told her friends. "I need everypony to stay behind me. I'm the leader for now."

"What happened between you two?" Fluttershy asked, wondering why Princess Celestia and Luna are not with each other. "Me and my sister got into an argument, and she was very upset." Princess Celestia replied back, much to the others reacting in shock to what she just told them.

"Can you explain a bit more?" Twilight Sparkle asked Princess Celestia, wanting more explanation from her former teacher. "During the argument between us, I think it was when I said something bad about her."

"Like what?" Pinkie Pie questioned. Princess Celestia responded back, saying, "She said that I was not a better princess, and that also made me upset, so I said the same thing back to her."

Rainbow Dash pointed her hoof to the moon, seeing a pony next to it. "Everypony, look!"

"Can it be… Princess Luna?" Princess Celestia wondered, knowing that it has to be her sister and not anypony else. "If that's Princess Luna in the sky, then let's get the hay movin'!" Applejack told her friends, as they had hurry as much as they could, otherwise, it'd be too late for them to catch Princess Luna.

Princess Luna started transforming into her dark side, thus things are too late. "Hahahahaha!" Nightmare Moon evilly laughed, as she was free again. "Now that I'm back, I'm gonna have a surprise for my sister and her friends when they arrive because I will put an end to all of them!"

While Nightmare Moon was waiting for the others to come near her, she used her magic to make herself bigger, therefore making her even more dangerous for Twilight Sparkle and her friends to prepare for the battle against her. "This will be a perfect opportunity to test on those puny ponies as they get here." Nightmare Moon said, as she was waiting for the others to come.

"This way!" Rainbow Dash shouted, as she found the path that will help them find Princess Luna.

As they got there, Twilight Sparkle and the others gasped in shock of Nightmare Moon's appearance, who was more powerful and frightening than before. "I've waiting for you ponies to come." Nightmare Moon told the ponies that stood in front of her. "Now suffer!" She said as she unleashed an attack on the ponies.

"Stand back!" Princess Celestia warned the others, as she guarded them and herself from Nightmare Moon's gigantic blast using a barrier, only to be broken because of how big Nightmare Moon's blast was. "Do you fools think you're a match for me?!" Nightmare Moon angrily raised her tone.

"We've defeated you once and we can do it again." Rainbow Dash told the gigantic-sized Nightmare Moon, as she knew that they could defeat Nightmare Moon for a second time.

"Unfortunately, that won't be happening again." Nightmare Moon said, as she was now powerful to destroy both Princess Celestia and the Mane Six with her enormous size.

"We came too late for this…" Fluttershy said in fear, who began to run for her life when Nightmare Moon slammed her hoof down, causing the ground to shake a little like an earthquake, even Fluttershy was knocked out unconscious in the process.

"Fluttershy!" Rainbow Dash yelled, as she began to fly towards Fluttershy. She noticed that Fluttershy was unhurt, but could not move due to Nightmare Moon slamming her hoof loudly. "Oh, no, she's not speaking!" She told her friends. "We're getting out of here, now!" Applejack told Pinkie Pie and Rarity as they, along with Rainbow Dash and Fluttershy, had to leave the fight between Twilight Sparkle and Princess Celestia against the giant Nightmare Moon.

"Twilight, you and I will deal with Nightmare Moon." Princess Celestia told Twilight Sparkle, as they knew they had to fight as much as they can against Nightmare Moon. "Ah, but two against one is hardly a fair fight." Nightmare Moon giggled. "But if that's the way you both want things to be, then I guess there's no point of wasting time…"

Nightmare Moon began to rush at Twilight Sparkle and Princess Celestia, loudly shaking the ground. "Here she comes!" Princess Celestia reminded Twilight Sparkle. "Teleport us, quickly!" She told Twilight Sparkle.

Twilight Sparkle teleported Celestia and herself away from Nightmare Moon's rushing speed. "Phew, that was close…" Twilight Sparkle said to herself, as she and Celestia hid themselves from Nightmare Moon, but it wouldn't last for long until Nightmare Moon would find them before destroying them both.

"Huh? Where'd they go?" Nightmare Moon wondered, as she did not see Twilight Sparkle and Princess Celestia in front of her. "Come out!" She yelled. demanding the two ponies to come out immediately.

"Stay put." Princess Celestia silently warned Twilight Sparkle, suggesting that they did not make a noise.

Nightmare Moon continued walking, shaking the ground each time she made a stomping sound. "You can't hide from me forever!" She shouted, as she was not to be fooled by these games. "When I find you, you'll be asking for your demise."

Although Twilight Sparkle and Princess Celestia neither made a sound nor a move, Nightmare Mare eventually found them regardless, allowing her to attack the two ponies while hiding from her. "I got you now!" Nightmare Moon said, as she prepared to destroy the two ponies with her blast. "Uh oh, we gotta get moving!" Princess Celestia told Twilight Sparkle, as they started flying in the air, and try to fly away as much as possible.

"Flying won't get you anywhere!" Nightmare Moon told Twilight Sparkle and Princess Celestia, who both ignored what she was saying, and chased after them.

Throughout the sky, Twilight Sparkle and Princess Celestia tried the best they could to get away from the giant Nightmare Moon. "Behind you!" Nightmare Moon called out, unleashing a number of magic blasts at the two ponies. "Duck!" Princess Celestia told Twilight Sparkle, as they ducked Nightmare Moon's enormous blasts.

"How clever that these ponies are small, but yet I'm bigger and have the upper advantage." Nightmare Moon said to herself in mind. "Perhaps I better go in front of them so that they don't outsmart me this time." She said, using her magic to teleport in front of Twilight Sparkle and Princess Celestia.

Twilight Sparkle and Princess Celestia gasped in shock again as the giant Nightmare Moon appeared in front of them, giving her the chance to destroy them completely. "You first!" Nightmare Moon said to her sister, as she aimed her blast at Celestia, causing her to be knocked out unconscious.

"Celestia!" Twilight Sparkle said in shock, as she saw Princess Celestia fall down after being hit by Nightmare Moon's single blast attack. "Looks like it happened again…" Nightmare Moon said as she watched her sister fall to the ground for a few seconds before leaving the scene.

As Princess Celestia fell to the ground, Twilight Sparkle came to her, feeling sad. "I can't let Nightmare Moon get away with this…" She cried as tears began to come out of her eyes, though she still went after Nightmare Moon regardless, leaving Princess Celestia behind.

Nightmare Moon, on the other hand, planned on going after Twilight Sparkle's friends, unaware that Twilight Sparkle herself was going after her, too. "Twilight's friends may have ran off earlier, but they'll be next on my list. After all, they, too, will suffer the same consequences like how I did with my sister."

"Nightmare Moon!" Twilight Sparkle shouted with anger, unleashing a magic blast at Nightmare Moon, who looked back in surprise. "What?! Impossible!" She said in shock, as the blast started shrinking her, making her unable to find Twilight's friends.

"That does it!" Nightmare Moon yelled with anger as started to rush at Twilight Sparkle with full speed. However, Twilight Sparkle, teleported herself before Nightmare Moon could attack her. "I've had enough of this!" Nightmare Moon yelled again, enraged even more.

Twilight Sparkle finally unleashed a magic beam at Nightmare Moon, hitting her, causing to revert back to Princess Luna.

"What happened…?" Princess Luna asked as she felt dizzy from the blast Twilight Sparkle unleashed. "You're back to your regular self now." Twilight Sparkle told her, as she freed her from Nightmare Moon taking over her body permanently. "Let's go back and find Princess Celestia. I'm sure that she has to be awake by now."

Twilight Sparkle and Princess Luna head back to find Princess Celestia still on the ground. Princess Luna lowered herself to the ground and walked up to her sister. "Sister, can you hear me?" She asked.

Princess Celestia opened her eyes, and saw Twilight Sparkle and Princess Luna in front of her. "Where am I…?" She said to herself. "Well, you are safe, Celestia." Twilight Sparkle told her, as she helped her get back up.

Several minutes later, Twilight's friends came back to check on her, Celestia and Luna. "Twilight, you alright, sugarcube?" Applejack asked Twilight Sparkle, wondering if she was okay. "It's alright." Twilight Sparkle responded back. "Nightmare Moon's back to Princess Luna now thanks to me, so everything's almost solved."

"I still owe you an apology from earlier, sis." Princess Luna apologized to her sister with regret about the argument they had in Canterlot. " I accept your apology, sister." Princess Celestia said, as she was also sorry for the argument.

"How about I treat everypony to some donuts?" Pinkie Pie asked her friends. "Count us in!" Rainbow Dash agreed. "Nope, me and my sister are fine…" Princess Celestia told the Mane Six, denying the trip for some donuts on the way back, instead preferred returning to Canterlot.

As the two Royal sisters headed straight for Canterlot, the Mane Six decided to go to the donut shop for donuts. "It was a tough day, but it had to be done." Applejack said to her friends. "Yeah, but I'm sure that another day will be a better day." Fluttershy told her friends, while they laughed their way heading for the donut shop.