//------------------------------//
// Looking Into It 
// Story: The Second Pony to Become an Alicorn 
// by Razor Blade the Unicron 
//------------------------------//

"N-Nightmare Moon?" asked Rainbow out loud in shock. "Shadow?"
Without responding, Nightmare Moon blasted a beam of magic up at the ceiling, cutting a large hole in it. The stone fell down, and Rainbow quickly dove out of the way of it before it could hit her. She quickly flew up to Nightmare Moon, with a nervous look on her face.
"Luna, what's going on?!? Why is Shadow in control of you again?!?"
Again, Nightmare seemed to ignore her, and looked pasted Rainbow.
"Luna!" Rainbow turned around to see Celestia with a sad expression. "I will not fight you! You must lower the moon! It is your duty!"
"Luna?" asked Nightmare. "I am Nightmare Moon! I have but one royal duty now," her horn flared up with magic, "To destroy you!"
She blasted a beam of magic off at Celestia, who flew into the air to dodge it. She zipped out of the hole in the ceiling, and Nightmare grinned.
"And where do you think you're going?" she asked, spreading out her wings to fly after her.
"Don't!" cried Rainbow, quickly reaching out and grabbing at Nightmare's leg. However, her hooves simply moved through her leg, and her eyes widened in realization. "This is a vision..."
Nightmare took to the sky after Celestia, and Rainbow followed after her. Nightmare continued to blast beams of magic at Celestia, which were continually missing and instead destroying the castle below. She finally managed to hit Celestia, who let out a cry of pain before crashing down into the castle. Rainbow's first instinct was to dive after her, but she paused when Nightmare's head abruptly jerked.
"Celestia?" asked Nightmare, but in Luna's voice. "Sister?"
Nightmare's head jerked once more, and she let out a cackle. Rainbow flew down towards where Celestia had crashed, just in time to see her shakily standing up. Celestia frowned sadly, and walked over towards the center of the room she was in.
"Oh, dear sister." said Celestia out loud. "I am sorry, but you have given me no choice but to use these."
Her horn lit up, and an odd contraption came out of the ground. It opened up, and Rainbow's eye widened in realization.
"The Elements..." she said softly, as Celestia grabbed five in her magic. "This must have been the night you banished her..."
As soon as Celestia had the five Elements of Harmony, the sixth one came out. It was identical in shape and color to Twilight's cutie mark. A tear slid down Celestia's cheek as she flew into the sky, the Elements spinning around her to form a rainbow ribbon. She flew into the air until she could look Nightmare straight-on, and Rainbow followed into the sky. Nightmare blasted huge beam of dark blue magic towards Celestia, who quickly put the Element of Magic in front of her, and centered the magic of each Element of to it. A beam of rainbow-colored magic blasted out to meet Nightmare's magic, and it began to push her's back. Nightmare's eyes widened in realization as the magic of the Elements met up with her.
"NOOOOOOO!!!" she cried as she was abruptly blasted high into the sky by the Elements, with a shock wave similar to the Sonic Rainboom. A pattern of spots appeared on the moon, that exactly matched the pattern of the Mare in the Moon.
Rainbow blinked, and a moment later she found herself back in Ponyville. Everypony was staring nervously at her, and Rainbow blinked in confusio
"Uh, why are you all staring at me like that?" she asked.
"It's just... you were mumblin' to yourself." said Applejack.
"And you cried a bit at one point!" said Pinkie.
"We were just really worried about you." said Fluttershy.
"Well I thought it was so underwhelming." said Discord casually. "Honestly, you only had one tear the whole time!"
"I did?" asked Rainbow, putting her hoof to her cheek to check. "Huh."
"What did you see?" asked Twilight. "Do you know what we need to do?"
"Well... I saw something from a long time ago... It was when Celestia had to banish Luna to the moon..."
"Perhaps farther back still are the answers you seek." said Zecora, holding out the potion to her. "Another sip of the potion will give you a peek."
Rainbow nodded, and quickly took another sip of the potion. Discord abruptly appeared in front of her with a camera, and a cheesy photographer's outfit.
"Oh, I do hope you break into song this time!" he said with a grin.
"Not a chance." said Rainbow, before her eyes glowed white once again.
She blinked, and found herself standing on a checkered ground, with a magenta sky above her. A school of fish swam by her, and Rainbow sighed.
"Discord..." she muttered, before turning around to see Celestia and Luna walking up towards him, each with loaded saddlebags.
"Oh, this is so much fun!" said Discord, abruptly pulling out something that resembled Celestia's tail. "Who wants to play pin-the-tail-on-the-pony?"
Luna glanced back to see that Celestia's tail really was gone, and gasped in surprise. Celestia glanced back, and also gasped in surprise, before turning back towards Discord.
"Playtime is over for you, Discord." said Celestia angrily.
"Oh, I doubt that." said Discord, who was casually munching on a bunch of black seed-like stuff. "Hungry?" He tossed some over to Celestia and Luna, who simply glared at him. "Suit yourselves."
Wait a second, thought Rainbow as the three continued talking, Black seeds? 
She walked over to where Discord had just thrown some more of the seeds, and watched as they buried themselves in the ground, sprouting out thin black vines with tiny blue spikes.
"Vines..." she muttered angrily. "Discord, I can't believe you..."
A flash of light from behind caught Rainbow's attention, and she turned around just in time to see the Elements turn Discord into stone. There was another flash of light, and Rainbow found herself standing next to a large, crystalline tree with five gemstones on the branches.
"The Elements?" she asked out loud, as Celestia and Luna walked up from behind.
Luna gasped in surprise at seeing the tree, and spoke in awe. "The Tree of Harmony..."
The Tree of Harmony?
"Are you sure?" Luna asked Celestia nervously.
"We have managed to discover the only means by which we can defeat Discord and free the citizens of Equestria." said Celestia, carefully taking out the gems with her magic. "Even without these elements, the Tree of Harmony will possess a powerful magic. As long as that magic remains, it will continue to control and contain all that grows here."
A star shape in the center of the tree opened, to reveal the sixth Element, which matched the star shape.
Those both look like Twilight's cutie mark! How did I not notice that before?
In an instant, Rainbow was brought back to Ponyville, where her friends were all staring at her anxiously.
"What did you find out?" asked Twilight.
"The Tree of Harmony is in danger." said Rainbow.
"The tree of what-now?" asked Applejack.
"It's where the Elements came from. It's in danger because of these stupid vines!" She angrily turned towards Discord, who was just casually floating in the air. "And you're the one who planted the seeds!"
"Rainbow, you shouldn't just accuse Discord like that..." said Fluttershy.
"I saw him in the vision! He was throwing black seeds everywhere!"
"Why, I was just having a snack." said Discord.
"Then why did the seeds bury themselves and start growing?!?"
"Well-"
"I don't want to hear it!" Rainbow stamped her hoof on the ground. "Just make the vines go away! You planted them, now you need to get rid of them!"
Discord laughed nervously. "Actually... You see, I did try that to get rid of one of the vines, except... I can't get rid of them."
"And why not?"
"Some other magic has been infused into them, and I can't get past it!"
"What kind of magic?"
"Dark magic."
Rainbow's pupils shrunk to pinpricks, and she stopped moving around. Starlight walked up to her, and gently placed a hoof on her back.
"You can just use the Elements to get rid of the dark magic." she said comfortingly. "It's not an issue."
"Can't use the Elements unless the Tree of Harmony is okay." said Rainbow. "And do you know what it means when there's dark magic? Do you know who's always behind it?"
"Rainbow, I'm sure it's not-"
"It's always Shadow!"
The vines all glowed in a dark red magic in response.