Twilight tumbled through darkness, pulled down what felt like the funnel of a tornado. All around her she caught vague snatches of light and sound, familiar and unfamiliar voices and faces. At one point she thought she saw Starswirl the Bearded, and then the Castle of the Two Sisters in an intact state, and she realized she was inside Celestia's memories.
"Over here!" Luna shouted from somewhere in the abyss, sounding very faint and far-off.
Twilight spread her wings and stumbled toward the princess's voice, buffeted from all directions by a storm of shadow. Was this what the inside of a pony's mind looked like when a Nevermind had infected it? "I'm coming!" she shouted, although the words seemed to be snatched right out of her mouth and carried away into nothingness.
Amid the maelstrom, a light shone, either very small or very far off. It was the only constant in the chaos, so Twilight followed it despite invisible forces tugging on her, slowing her, trying to make her turn away.
A wing wrapped around her. "There you are," Luna said. "I was worried we'd lost you. Celestia's mind is in a terrible state."
The light bobbed and turned out to be coming from Radiant Dawn's horn. "We've got to find Celestia," the light blue alicorn said. "Luna, if anypony can track her down, it's you."
Luna looked surprised, but nodded. "R-right," she said. "Follow close!" Spreading her wings, she tossed her mane and plunged into the howling shadows.
"Why can Luna find her?" Twilight asked Radiant Dawn as they tailed the moon-alicorn. Celestia's mind was in such disarray that Twilight had to shout just to hear her own voice.
"Because Luna is the Princess of Dreams," Radiant Dawn shouted back, "and because she is Celestia's sister. Her heart will lead her."
Far in the distance, Twilight saw another light, this one dim and fuzzy like the sun behind fog. "Celestia!" Luna called, hastening her stride.
Celestia was curled into a ball, surrounded by deep roots of shadow, hooves over her face. The light that usually emanated from the alicorn was faded and flickering. At the sound of her sister's voice, her ears perked and she looked up. "L-Luna?!" she yelled. "Is that you?!"
"And me!" Twilight said, beating her wings to reach the princess. "And Princess Radiant Dawn, too!"
Celestia's eyes widened. "Twilight! Radiant Dawn!" she said. "What are you doing here?"
"Saving you, that's what," Radiant Dawn said as the three alit next to Celestia. "You have to fight back against the Nevermind!"
"Is that what's doing this?" Celestia asked, looking around at the raging darkness. She grimaced. "Maybe I shouldn't…"
"What do you mean, maybe you shouldn't?!" Twilight asked. "Why in Equestria would you let the Nevermind win?"
"I'm… I'm afraid," Celestia said quietly. Again she looked up, and Twilight saw that the princess was surrounded by memories. Many of them looked to be recollections of her many battles against evil - including the time she banished Nightmare Moon – but there were also memories of Celestia's nightmare of becoming Daybreaker, and those seemed especially vivid.
Radiant Dawn put a hoof on Celestia's shoulder. "What scares you?" the blue alicorn asked.
Celestia swallowed hard. "I'm afraid I've grown too powerful," she said. "What if I decide to use my powers for evil, selfish purposes? All it takes is one wrong choice… and then I'll turn into that." She pointed to a Daybreaker memory with a trembling hoof. "I could cause such tremendous destruction and misery across Equestria… perhaps it's best if I don't rule at all—"
"I think that's rubbish!" Luna said, stomping her hoof. "You're being far too hard on yourself! One does not just randomly turn evil—take it from me! You have a choice, Celestia! And you always choose good! I know it's hard for you to trust yourself right now, but trust me! Trust your sister! I love you and I know you better than anypony else!"
"And trust me!" Twilight Sparkle said. "You can't worry about the future all the time, it'll drive you crazy!" She paused. "Orrrrr you'll end up breaking into the Canterlot Archives to research time travel spells. Just take it from me, it never ends well. And you definitely shouldn't waste any time worrying about a future that you can actually control!"
A small smile eased Celestia's features. "Thank you… both of you," she said. Her smile faded and she shuddered. "But… I still…"
"Don't give in, Celestia," Radiant Dawn. "That's exactly what the Nevermind wants. That's exactly what all the evil in Equestria wants. It knows you'll never use your powers for ill, so the only way it can get to you is to try to make you doubt yourself." Her horn flared. "You deserve to be happy, Celestia, so fight it!" she neighed. "Take it down! Make it sorry it messed with you!"
Streams of light spread from Radiant Dawn's horn and whipped into the shadows, pulling in other memories of Celestia's—scenes from a peaceful and secure Equestria, acts of kindness and selflessness Celestia had performed over the centuries, and the looks of love and gratitude in her subjects' eyes as they gazed upon their benevolent ruler. There were also memories with Radiant Dawn in them, where Celestia seemed to be giving the other alicorn comfort and advice, and Twilight realized how much Radiant Dawn truly appreciated the princess.
Celestia gazed up at the happy memories, and suddenly her eyes hardened and her nostrils flared. Taking a deep breath, she pushed herself to her hooves. "I may not know the future," she breathed, "but I know myself… and I know I would never allow myself to fall!" Rearing back, she sent out a beam of light from her horn that cut through the shadows and sent the memories flying. "I am not Daybreaker!" she cried. "I am Celestia, champion of good—Princess of Hope!"
The darkness converged on her again, but Celestia's eyes glinted dangerously and she fired another blast of magic, plowing a hole through the tangle in her mind. She turned her head and threw out more magic in a different direction, thinning the darkness bit by bit.
The overload of light began to blind Twilight, and as she squinted, still trying to see Celestia, she felt a wing around her and then she was pulled upward and outward.
With a jolt, Twilight landed back in her own body, and she staggered back, wobbling on her hooves. Radiant Dawn took a moment to get her bearings as well, but then their attention turned to Celestia.
The alicorn's glow steadily brightened, and she frowned as she twitched and breathed hard. The Nevermind's shadows arced around her body, frantic and panicked. Then, an immense blast of light magic surged from the princess like a solar flare. The Nevermind screeched in a noiseless voice that seemed to shake the entire palace—and then it was gone.
The light slowly faded. Luna stepped back in shock, while Ironclad put a wing around his wife and she leaned against him. Twilight Sparkle just watched Celestia with bated breath.
Celestia opened her eyes. "I'm free," she said breathlessly.
"Celestia!" Luna hugged her. "I'm so glad you're all right! I was so worried about you!"
"I'm so sorry," Celestia said, hugging her back. "I never meant to make you worry—I never meant for any of this…" She looked up at the other two alicorns. "And thank you for your help, Twilight Sparkle and Radiant Dawn. It's good to see both of you again."
Radiant Dawn ducked her head. "Celestia, I'm so sorry," she said. "I would have gotten here sooner, but… well, I was a coward. I was so scared that I was weak and useless that I refused to think I could help you. It was only after they reminded me of who I really was that I came to your aid."
"Oh, Radiant Dawn…" Celestia eased herself to her hooves. "It is I who should be sorry. I think that was my fault. In hiding you from the outside world, I was trying to protect you, but I think instead it just made you assume you were weak."
"You had good intentions," Radiant Dawn said. "This is all my fault. I overthought things way too much and dug myself into a hole."
Celestia shook her head. "But maybe you wouldn't have done so if I hadn't left you to your own devices," she said. "I've learned from my experiences with Twilight, Luna, and Cadance that princesses need a support network. I shouldn't have kept you out of the loop so much."
"It wasn't like I actively asked you to include me more in princess things," Radiant Dawn said. "But once again that was due to my own lack of confidence, so I'm to blame for my miserable state."
Celestia paused and smiled. "Let's just agree that we both made some mistakes," she said, "but we've learned from them and that's what matters most."
"I can agree to that," Radiant Dawn said, returning her smile. "I'm so glad you're all right. And I'll never shirk my duties as Princess of Happiness again."
Celestia laughed. "After what I did," she said, "I can't ever judge anypony for shirking her duties. But rest assured that I won't let this happen again."
"If it helps any, Your Highness," Starlight Glimmer said, scratching her foreleg with her hoof, "I've learned that sometimes we need to do something wrong in order to learn how to do it right. If that makes any sense."
"It does," Celestia said. "Thank you, Starlight. I hope there haven't been any severe problems in my… absence."
"Well, apparently some ponies are starting rumors that Luna's to blame for what happened to you," Spike said. "You'll probably wanna fix that."
Celestia nodded. "Oh yes, right away." She moved to the door. "But after that… how would you all like to join me for a birthday luncheon?"
"Absolutely!" Twilight said.
"We would be honored," Radiant Dawn said, nodding to Ironclad. "And, Celestia… can we take the spell off of Daybreak now?" She took a deep breath. "It's time I showed Equestria my true strength. I'm just as much an alicorn as the rest of you."
Celestia's smile widened. "Indeed you are, Radiant Dawn," she said. "I will accompany you and Ironclad back to Daybreak when you are ready to return home. Until then, please enjoy everything Canterlot has to offer you—and enjoy your status as a princess."
"I will," Radiant Dawn said.
Celestia moved to step into the hallway—and Pinkie Pie cut her off. "Wait!" the earth pony said. "I have to wish you a proper happy birthday! I wanted to when we first got here, but you were all like 'blah' and the evil magic spirit thingie wouldn't let me wake you up to tell you happy birthday, and then we had to go alllll the way to Daybreak and back, so I'm four days late, but, happy birthday Princess Celestia!" She threw confetti and streamers at the princess.
"Why… thank you," Celestia said, pulling a few streamers off of her head. "I don't know what to say. Really."
Pinkie's ribs heaved as she panted to catch her breath. "Also… what color… balloons… do you like?"
Celestia laughed. "I'd have to say I'm fond of yellow," she said. "But any color will do just fine. I want you to enjoy my birthday too, Pinkie Pie."
"Oh, I'll enjoy it," Pinkie said, "just as soon as I know you're enjoying it!"
"I'm already enjoying it!" Celestia said, clearly just as amused as she was bewildered.
Everypony else began to laugh. Twilight looked around at her friends' happy faces – and at the happy faces of the princess and prince of Daybreak – and her heart lifted. It felt as though clouds had broken up and let the sun shine through. And she knew that whatever darkness might try to threaten Equestria, its stalwart alicorn guardians, working together, would always triumph.