The Harmonic Oath
Twilight tapped Spike, who was cuddled up in his bed, but his blanket not wrapped around him. Spike rubbed his eyes and hopped out of bed.
''Come on, Spike,'' said Twilight. ''Get yourself together. We don't want to be late for the Summer Sun Celebration, because this marks the fact it's the 1-year anniversary of the time we defeated Nightmare Moon and met our friends.''
''I remember you putting my blanket in the wash room,'' Spike mumbled. ''Now would be a good time to fetch it.''
''Oh, yeah... I almost forgot.'' Twilight levitated a blue blanket off of her clothsline as they went outside.
''Come to papa--'' Spike tried to grab the blanket, but Twilight levitated away from his grabbing distance.
''We can't take your blanket to the festival,'' Twilight said, '''cause this needs to stay here. You don't want it to get lost, do you?''
Spike crossed his arms. ''Fine.''
Twilight grinned and levitated the blanket neatly onto Spike's bed. Spike tried to run towards it, but Twilight held him back with her hoof.
''Spike, we're already late,'' Twilight said, in reply to his action. ''You'll see the blanket later.''
''As in tomorrow.''
''Spike!'' Twilight dragged Spike with her magic across the Ponyville village. ''Now we're later than ever. I hope the Princess and my friends can forgive me.'' Spike grunted.
''Let go of me!'' he complained. Twilight dropped him. Spike stared at her blankly and frowned. But then he smiled and said, ''Hey, we're here already!''
''Huh?''
Twilight looked around. Streamers and ribbons were placed neatly onto the Summer Sun Celebration location, Ponyville Tower. Ponies were eagerly trotting inside, and from the corner of her eye, Twilight saw her 5 friends next to the door.
''Sorry I'm late, everypony,'' said Twilight. ''Terribly sorry.''
''That's okay,'' said Rainbow Dash. ''The Celebration hasn't even started yet. It won't start for about another 3 minutes.''
''I would have got here ten minutes ago,'' Twilight said, ''but Spike--'' She stared at Spike then looked back at her friends. ''--Spike wouldn't hurry up to get ready.''
''That's fine, Twi,'' said Applejack, ''Apple Bloom wouldn't get up either.''
Apple Bloom, who sat next to Applejack, smiled sheepishly. Her face turned slightly red, then white.
''I couldn't fall asleep,'' the filly explained. ''The Crusaders and I tried to have a staying-up-late contest, and after we finally went lights out, I couldn't fall asleep.''
''I don't blame you,'' said Twilight. ''As a filly, I couldn't fall asleep either. The excitement of the Summer Sun Celebration just kept me up half the night. Every year.''
''As long as you're here,'' Pinkie Pie said, ''and the Celebration hasn't start yet, we should go chow down!''
''I thought that comes after the Celebration,'' Applejack said.
''Like it even matters,'' Rainbow said, nudging Applejack and grinning.
''Um, okay?'' Twilight said as she watched Pinkie, Applejack, and Rainbow trot to the food table. She looked at a yellow mare, Fluttershy. ''I can't wait to hear your birds sing, Fluttershy! I'm sure they'll do as good as last year.''
''Thanks, Twilight,'' said Fluttershy. ''But it's not my birds singing this year.'' Twilight raised her eyebrow.
''No?''
''Rarity offered her yard birds to sing this year.''
''Um...'' Twilight looked at the stage. ''Hey, the Celebration's starting!''
The chatter in the audience quieted down as Rarity's birds sang their opening tune. The spotlight moved onto the Mayor of Ponyville.
''Fillies and gentlecolts...'' the mayor said. ''We are proud to have you here today. As you all know, the Summer Sun Celebration is a festival regarding the longest day of the year!''
Cheering came from the audience.
''Here we will have our beloved Princess of Equestria raise the sun to bring forth the special day,'' the mayor went on, ''so, without further ado, here is our Princess of the Celebration, Princess Celestia!''
The curtains opened, but the space was empty. Dark. Alicorn-less.
''For the second year in a row?!'' Rainbow yelled. Murmurs scattered through the audience.
''There must be an explaination for this,'' the mayor said. ''This can't be happening again.''
''Maybe Nightmare Moon's loose again!'' called a voice from the audience. Twilight's heart raced at the thought.
''I don't think so,'' said Twilight, with the courage to speak out. ''I promise I'll find out what's happening. Don't worry.''
She ran out the doors, with her friends chasing after her.
''Twilight! Take us with you!'' Applejack said.
''No,'' Twilight replied. ''I'm doing this quest by myself. Don't worry about a thing. Tell the audience and the Mayor to relax while I get things straightened out.''
Her friends nodded and ran back into the tower.
***
As soon as Twilight arrived in Canterlot, she pushed open Celestia's castle doors. The Princess stood staring out her windows, back turned away from Twilight.
''Princess Celestia?!'' Twilight exclaimed. ''Why aren't you at the Celebration?''
''I can't go, can't take my eyes off the land,'' said Celestia. ''He has returned.''
''He who?''
''King Sombra.'' Celestia turned around at looked at Twilight.
"What?!'' Twilight's eyes seethed with rage and hope. ''But-- How?''
''King Somber has enough power, but not enough to beat the Crystal Heart. After his defeat, a powerful spell unlocked the full power of himself, causing him more power than ever.'' Twilight looked outside.
"I don't see anything wrong with Equestria.''
''Not now, but after King Sombra finds out you, Spike, and Princess Cadance live here in Equestria... It will be all over. The only way to protect Equestria is to unlock the power of the Diamond Ponies.''
''The... Diamond Ponies?''
''A thousand years ago, they spoke the Harmonic Oath. It gave them the power to defeat anything. But what they didn't know was that the Oath sent out a spell that spread through the whole realm of the Diamond Empire, causing them to fall asleep for a thousand years.''
''Does that mean they've returned?''
''Yes.''
''Then... I have to find the Diamond Realm before Somber returns and corrupts Equestria. You need to get to Ponyville Tower, raise the sun, and tell my friends what I'm doing and where I'm going. It's not too late to raise the sun, it's only 5:30 in the morning.''
''Very well.'' Celestia walked to the doors. ''Oh, and before you leave, here's a map.'' Celestia tossed a scroll to Twilight. ''The most important thing you'll need to know where you're going.''
''Alright. You'd better get to Ponyville quick!''
''No worries. I'll teleport. Good luck, Twilight. Are you sure you're capable of handling this situation?''
''Mm-hmm.''
''Then go. The fate of Equestria is in your hooves.''
''Don't worry. I'll find the Diamond Realm in time.''
Celestia's horn glowed and in a flash, she was gone.