Here's a new story I hope everyone will like! Please review this! any criticism I can take, it can't be as bad as my sisters (big pains in the butt) are.

Enjoy!

"Twilight, hurry up!" Applejack called. The orange pony fidgeted with impatience. "We're going to be late for our train!"

Princess Twilight Sparkle and her five friends were going to Canterlot to celebrate the 5th anniversary of the beginning of their friendship on the Summer Sun celebration. The princess, however, was in a tizzy. No matter how often she helped with the celebration, Twilight couldn't shake the feeling that something big was going to happen, given that it was two weeks before the actual celebration and Princess Celestia had urgently called them to Canterlot. The young princess searched her room for everything that the friends could possibly need while in Canterlot.

Once she had quadruple-checked everything, she finally relaxed a little. She came out with many overstuffed bags on a wagon behind her. Spike, her faithful dragon assistant, pulled the wagon easily. After so long with Twilight, his muscles bulked up and he became stronger with age. Applejack relaxed as well when she saw Twilight come out. They walked to the station, where their friends were waiting for them, calling over to show them their saved spots.

In the Avengers tower, Tony Stark paced with anticipation. Director Fury had announced that the Avengers was getting another member and that he was escorting their new teammate to the tower personally. Thor was nervous, too, fidgeting and turning Mjollnir over and over again in his hand. Clint Barton was looking for something to eat in the fridge, but didn't succeed. Natasha Romanov was nowhere to be found, and Hulk was trying to stay calm. They didn't know why, but something in the air told them that their whole world was going to be crashing down on top of them.

Back in Canterlot, the six friends were departing their train and heading towards the castle, wondering what reason Celestia had for calling them to Canterlot so early. When they arrived at the castle, they rushed to Celestia's throne room. After they gave the customary bow, Twilight asked, "What's going on? Is there something wrong?"

Celestia, looking crestfallen, replied, "Do you remember the mirror that I showed you a few years ago?" When Twilight nodded, remembering all the human versions of her Ponyville friends, Celestia continued, "It is in danger once more. The Crystal Heart has been stolen from the Crystal Empire. We need you to go through the mirror and get it back before its captor can use it to destroy that world."

Twilight asked, "What did the thief look like?" remembering Sunset Shimmer, who had stolen her crown and Element of Harmony the last time the portal opened.

It was Luna who answered, "It was an alicorn like us, but it had green skin, black mane and tail, and a swirl of snow as its cutie mark. It wore gold armor with horns on the helmet. Is that enough information?"

When Twilight nodded, Celestia explained, "I talked to one of that world and they will help you apprehend the thief."

Luna added, "Last time you went through the portal, you went near the end of the week. This time, you have six days to find the Crystal Heart before the portal closes. Are you ready to go through it again?"

Twilight thought for a moment, then made a decision. "I'll go. Wish me luck."

Celestia put a bag on Twilight's back and saw her off. Twilight took a deep breath and went through the portal.

What do you think will happen? Please leave your speculations in the reviews! Please review!