Twilight paced angrily around the floor of Golden Oaks Library, having recently returned from Canterlot. She wheeled around to face Spike.
"How could they do this?" she muttered furiously. "Discord's barely proven that he's changed. How do we know he'll help? Honestly, don't Celestia and Luna trust me?"
Spike tapped his claws together. He always had to speak carefully when Twilight was in one of her moods. "I dunno, Twi," he offered. "Maybe they just don't think you're capable enough?" He winced as soon as the words left his mouth.
The princess stared at him in shock. "Look, I didn't mean--" he tried to backpedal.
"No, you're right, Spike," Twilight said in a disturbingly calm voice. "I've barely done anything since I became a princess. Maybe they're just waiting for me to prove my worth. Maybe they didn't say anything about this to me because it's all a test I have to pass!" She grinned maniacally with a gleam in her eye that sent a small dagger of fear into the young dragon's heart.
He decided to humor her. "So, what is this mystery test, then?" He inquired.
Twilight resumed her pacing. "Well, let's see. What's come up lately that would need solving? The Equestria Games are done, the Breezies have left, and there's-- Oh!" She stopped in her tracks, an idea throwing itself into her desperate mind. "Spike! Where's that blueprint I drew up a few weeks ago? And the box to go with it? That must be it!"
Spike disappeared up the stairs and through a door, emerging a minute later with a large, six-sided box and a roll of paper. He struggled back down the stairs, tripping down the last few steps and landing at Twilight's hooves.
Disregarding her assistant, she bent down to examine the chest. "Darn," she sighed. "It should have broken when you fell."
Spike dusted himself off and joined in examining the strange box. "So, your test is to, what? Open it? How are you supposed to do that?"
Twilight sighed. "I don't know, Spike. Maybe our friends will be able to help. It did come from the Tree of Harmony, after all. Maybe this has something to do with all six of us."
An hour later, Rainbow Dash, Pinkie Pie, Applejack, Fluttershy, and Rarity had arranged themselves in a rough semicircle around the mysterious chest.
Twilight stood in front of the assembly, wings flared in excitement. She resumed her earlier routine of pacing and began to explain her situation. "Alright, girls, I'm sure you're wondering why I asked you here," she began.
Pinkie waved a hoof in the air, as though she was a young filly in a classroom. "Ooh, oooh!" She shouted. "Is it because of the thing with Tartarus and Discord and you're mad because the princesses didn't pick you and obviously Princess Celestia doesn't think you're good enough to do anything that important and now you're thinking maybe this is all an elaborate test and so you're angry and you don't think Discord makes a good princess because pink really isn't his color and you decided that we need to try to open this magical box thingy that we got from that sparkly Tree way back like six months ago!"
Rainbow Dash snorted. "Yeah, that's totally it."
Twilight smiled. "Actually, she's exactly right. Now, I have no idea how I'm supposed to do this, but this came from the Tree of Harmony, so obviously it requires all six of us to open it. Because, you know, friendship and magic and stuff. So, any ideas?"
Applejack scratched under her hat, thinking. An idea seemed to enter her mind, and she spoke up. "Now, this might be crazier than Pinkie Pie, but Ah've got an idea. Ah dunno if anyone's noticed, but personally, Ah've been seein' these little rainbow things everywhere. Discord's flag, Pinkie's streamers, my Granny's pie tin, lots of places. But the first time Ah remember seein' 'em is when that there box showed up. And a few weeks ago Ah got a bit from somepony that sparkled with one'a them rainbows. It's a long shot, but if y'all have got somethin' like that, maybe it's got somethin' to do with it?"
Twilight scoffed. "Please, Applejack. I would have expected something that far-fetched from Rainbow, but not from you. You usually think things through more. A sparkly bit, really? It was probably just the sun."
Rainbow frowned. "You know, Spitfire gave me a pin that was all rainbow-y and sparkly. I figured it was just a reflection, but AJ's got a point." She paused a beat, then the rest of Twilight's words registered. "Hey! I'm not far-fetched."
Rarity cut across the pegasus. "You know, darling, I happen to have a spool of thread that shines. And I noticed that Pinkie's, erm, rubber chicken did the same when she got it."
Fluttershy nodded. "Seabreeze gave me a flower that did the same. That has to be it. Good idea, Applejack."
Applejack blushed. "Aw, shucks. It was a long shot; Ah really shouldn't take credit. Besides, how in tarnation are we supposed to fit all that stuff into those tiny little keyholes?"
Twilight spoke up again. "Seriously, that can't be it."
Rainbow rotated to glare at her. "And why not?"
The princess threw her hooves back in frustration, drew in her wings, and sat down. "Because, it's too crazy. Besides, I haven't gotten anything shiny lately."
Fluttershy pondered this. "You know, everything that led up to each of us getting our rainbow objects had to do with our element. Maybe that's it."
Pinkie jumped in. "Yeah! Like, it's the Tree's way of showing us that we're still connected to our elements, even though they're way far away in the Everfree Forest. And once we figure out a way to show that we're still connected, we get a little thing that helps us open the present we got from the Tree! You know, to like, show us that we're still amazingly good friends and stuff."
Rainbow screwed up her face in frustration. "What even is your element, anyway? Is it friendship or is it magic? I'm always super confused about that. Besides, I can't even think straight. You called me over here before I could eat lunch."
Spike jumped up from his seat on the floor, where he had been quietly observing the proceedings. "I could go get some snacks," he offered. He pattered out of the room and into the kitchen, clattering around.
Twilight looked at the kitchen door for a brief second, then turned her attention to the box again. "Okay, I'll humor you all," she grumbled. "I don't suppose you have those things with you, do you?"
Each of her friends' cheeks shone with slight embarrassment, and one by one they pulled out their mysterious treasures and set them on the floor in front of the chest. Twilight sighed and looked at them all, her eyes scanning the row in a vague attempt to understand them.
In frustration, she let her mind wander and cast a random spell on them. They rose into the air and became enveloped in a hazy rainbow of light. Suddenly, the light flickered and died, and the objects clattered to the floor again. But they had been changed into keys, and each key's color matched its owner's coat.
Applejack looked down at the orange key that had been a bit a minute before. "Well, Ah guess that answers that."
Twilight groaned loudly. "Yes, but how am I supposed to get mine?"
Just then, Spike returned to the main room. He carried a tray containing apples, cupcakes, and a bowl of gems for himself. "Hey," he called out. "I brought snacks for everypony."
Twilight levitated an apple and rubbed a hoof along his scales. "Thanks, Spike," she smiled down at him. "You're such a great friend. You're always there when we need you."
As she looked down at her very first and very best friend, she noticed a shine go down his scales. She looked up at the other ponies in excitement. "Did any of you see that?" she demanded.
Rarity bit her lip. "Twilight," she explained patiently. "You need to wait. I'm sure Spikey's scales were just reflecting something. You're looking into this too far, darling. You'll find it."
But Twilight wouldn't listen. "No, you see?" she explained. "This has to be it! Spike's always been there for me, ever since we were little and I hatched him. We were always really good friends, and we still are. Plus, he helps me learn about magic and stuff, and I hatched him with my magic. It all fits!"
Spike puffed his chest out as Twilight told her friends of his dependability, or so he thought. He had no idea why she was bringing that up. "Well, gee, Twi," he said. "We're all good friends here."
Twilight turned to him. "No, Spike, shut up. You don't know what we're talking about."
His face clouded over in confusion. "Then what--?"
His best friend interrupted him by lighting her horn and pointing it at him. "I'm really sorry about this, Spike," she apologized. "But it's for the best."
Her pony friends' eyes widened. They started to clamor for her to stop, but she didn't listen. She tried to think of what spell she had used earlier, but couldn't remember. She decided to use the same method and cleared her mind, casting the first spell that popped into her head.
Spike was enveloped in a cloud of rainbow light. "Wha--" he began, but his voice faded when the light wrapped around his head. A second later, the light dispersed, and a shiny purple key landed at Twilight's hooves.
"Well," she beamed. "That solves that. Let's get this sucker open."
Each of the ponies lifted up their new keys and shuffled around the chest. Six keys were inserted into six holes, and they waited for a command so they could turn them simultaneously. Twilight wrapped her key in her magic and shouted, "One, two, three, turn!"
Then the library exploded.