Luna stared in horror at the scene before her. Nightmare Moon stood behind Twilight with dark, star-specked tendrils of her mane curling around the unicorn. Twilight's horn was still glowing, keeping the shield bubble around her alive, but the strain was already showing on her face as the Nightmare tightened her magical grip.
"Release her!" demanded Luna, hoping she had hidden her fear.
Nightmare Moon laughed. "I think not." With one swift motion the misty tentacles of her hair crushed Twilight’s shield, which vanished even as it shattered, leaving Twilight exposed, vulnerable, and utterly burnt out, her horn tip actually slightly blackened from the backlash.
Luna's heart was in her throat. She took a step forward, her horn glowing. She had no idea what spell she could cast, but she had to do something.
"Ah, ah, ah!" The tendrils of Nightmare Moon's mane were wrapped around Twilight directly, and they tightened as Luna moved. "One more step and I'll wring her little neck."
Luna halted, trembling.
"That's better." Nightmare Moon sneered at her. Her mane wrapped around Twilight's throat, and Twilight let out a little choked sound as Nightmare Moon squeezed. "Now, release your magic."
Luna's horn blinked out.
"Very good," gloated Nightmare Moon. Her tail curled around and stroked Twilight's cheek. Luna could hear Twilight breathing; she was gasping, struggling for each breath. The sound seemed to reach somewhere deep within her, kindling a fear as strong as any she'd ever felt. The image of Twilight dead was the worst thing that Luna could imagine.
"Now, my dear little princess, you will kneel at my hooves. You will let me bind your magic, and you will answer all my questions about who you really are and how you have come here."
Luna hesitated. Part of her wanted to surrender. Most of her, in fact, wanted to do anything at all to prevent harm from coming to Twilight. Yet despite being half-choked, Twilight herself was shaking her head frantically. Twilight did not want her to give in. They had come so far, come so close, she couldn't possibly give up now. Twilight's life was not worth the lives of all the ponies in this world. They would die if Luna surrendered and Nightmare Moon won.
Or would they?
"Come now, I am not a patient mare. Surrender!"
"If I do, how do I know you won't merely kill her anyway?" asked Luna.
Nightmare Moon slackened her grip just a little bit, letting Twilight breathe. "I have no reason to harm her. She is only a unicorn. It's you that I want."
"No, don't do it!" said Twilight.
"Silence when your betters are speaking," snapped Nightmare Moon, and a tendril of her magic wrapped itself around Twilight's muzzle, holding it shut. Twilight glared at her and tried to cast a spell, but the magic sparkled and fizzled uselessly from her singed horn, making her wince in pain. What magic her struggle hadn't used the backlash had burned out of her; she had none left. Even if she'd had enough to do something, it would probably hurt too much to cast.
"It is all right, Twilight," said Luna. "Everything is going to be just fine." She felt a strange sense of calm settling over her. She needed to save Twilight, because it was Twilight who was necessary to their plan to defeat Nightmare Moon. Luna had already done her part by delaying and distracting the dark alicorn.
Yet there was more than that. She needed to save Twilight because she loved her. It was that simple, and that simple admission seemed to bring the whole universe into sharp focus. Love and friendship were different faces of the same coin. They were different halves of the same magic. The deep magic of Equestria, the harmony that made Celestia what she was and that Luna had somehow never been able to get a handle on, was built on love and friendship. That was why she'd never fully grasped it: she had always kept her heart apart. She had never fully trusted another pony, not even her sister.
But she trusted Twilight. She trusted her magnificent intellect. She trusted her skill with magic. She trusted her to be there, when Luna needed her. She could trust Twilight with her heart, and she could trust Twilight to save Equestria if she surrendered. All might seem to be lost, yet all could never be lost so long as ponies held to friendship and love.
All that flowed through her in a brief moment, an instant when it seemed like the universe itself was singing in her heart. Every part of it—even the moon that still spoke to Nightmare—told her that now she understood at last.
Twilight, frustration and fear twisting her gut as she watched Luna prepare to surrender, let out a sudden gasp as silvery moonlight blossomed around the blue alicorn. Nightmare Moon gasped too, and tightened her grip on Twilight's throat.
"Cease this at once or she dies!"
"Of course," said Luna, and her voice was gentle—serene. The light faded, and Twilight's eyes went wide in shock. Luna's mane and tail were no longer simply light blue hair that hung from her dock and poll like any pony's. They lifted and flowed on some invisible breeze, like Celestia's. They were darker than her sister's, layered with the deep colors of the evening sky, blue and indigo and purple. They were speckled with stars, like Nightmare Moon's, but the stars were far more beautiful, far more real somehow; as if Twilight could see straight into the fires at each one’s heart. She was taller too, perhaps as tall as Nightmare Moon herself, and her horn had lengthened as well.
"What trickery is this?" hissed Nightmare Moon.
"No trickery," said Luna. "Only truth,” she regarded the Nightmare solemnly, “and friendship.”
"Friendship?” growled Nightmare, “Nonsense! A nothing! A lie silly ponies tell themselves so they can pretend they are not alone! Have you forgotten what I hold here?" She lifted Twilight and shook her, making the unicorn whimper and clutch futilely at the strands around her throat. The chain that still connected her to the dais rattled and clanked with each shake.
"I could never forget that you hold that which is most precious to me," said Luna. She bowed her head. "I surrender to you willingly. I will swear whatever oath you require to accept your bindings, once Twilight is safe."
"Swear on the moon. She is listening."
"So she is," said Luna, her head still lowered, but a strange smile on her face. "I swear, on the moon and her maria, on her bright side and her dark side, on her dusty regolith and her cold heart, that I will surrender and allow myself to be bound, if you let the unicorn Twilight Sparkle go unharmed."
Nightmare Moon dropped Twilight. "I could almost believe that you truly are Luna. How do you know that oath?"
"I will not answer you, nor be bound by you, until Twilight is safe. Release her chains as well," said Luna.
With a wordless contempt, Nightmare Moon tossed her head, her horn sparking, and the chains fell from Twilight's hooves.
"Luna..." said Twilight, trying to come up with something useful to say.
"Do not worry, Twilight. Trust in the magic of friendship."
Twilight nodded.
A soft sound near the doors caught Twilight's attention, and she looked over to see Spike straightening from where he'd curled in a protective crouch beneath a small pile of rubble. He looked terrible, his face streaked with dust that tears had washed muddy tracks through. He looked at her and spoke, his voice tiny, vulnerable, as it echoed in the huge chamber. "Twilight? I... I'm so sorry. She lied. I didn't know she'd lied..."
"Spike, it's okay," said Twilight wearily.
"No, I rather think it is not."
Twilight's head snapped around to stare at Nightmare Moon. A length of magical chain already coiled around the surrendered Princess Luna. Now the Nightmare's horn glowed and her magic scooped Spike up into the air.
"I have promised to let you go, but I made no promises about him," she snarled.
"No! Put him down!" cried Twilight, her ears pinned back as sudden despair filled her.
Nightmare Moon threw her head back and laughed. "You ponies! You are so endlessly naïve. I am going to crush your every stupid little hope and dream, starting right-"
She broke off as a shockwave slammed into the throne room. For an instant the sky was filled with vivid color: every possible shade of yellow and orange twisted together in a brilliant arc of fire that washed over the palace, accompanied by a booming like thunder. When the blast front had passed, Twilight saw a glimmering ember, small and far away, but growing steadily, headed directly towards her.
Fluttershy's bats had led the quartet out of the crystal caverns in no time at all. After passing briefly through a paved corridor, they emerged high up on the mountain's slopes, above and behind the palace itself. "Yay! We're almost there!" said Pinkie, managing a bit of a bounce as she exited the cave.
Applejack surveyed the stairs that led down the mountainside. There were a lot of them, zig-zagging back and forth for quite some distance until they reached the palace gardens below. She sighed. "I dunno about 'almost', but I will admit I'm right glad ta' be out o' all them caves an' such."
"Yes, it is a delight to have some fresh air, such as it is," said Rarity. "For which we all owe Fluttershy a great deal."
"Oh, it's nothing," said Fluttershy, hiding behind her tangled mane.
"We still don't have Twilight, though," said Pinkie with a scowl. "Or Rainbow."
"Well, she ain't here on the mountain, so we might as well get a move on down them stairs." Applejack sighed again, but set off briskly enough, with the others following behind. Sounds of occasional combat floated up to them. It was no longer punctuated with explosions; the TNT seemed to have finally run out. Nevertheless, the fact that the rebels were still putting up a fight was a fairly hopeful sign to the four—even if everything else about the plan seemed to be continuously going wrong.
Both Rarity and Fluttershy were barely able to keep their feet at this point, so the pace was slow. They'd only gotten about half way down, when the scene below changed for the worse. The air was suddenly alive with dark-uniformed pegasi. The Shadowbolts had arrived.
All four ponies froze in place on the stair, not wanting to attract the attention of the horde of enemy pegasi.
"Aw horseapples," whispered Applejack. "What the hay are we supposed to do now?"
"I haven't the faintest," said Rarity, with a resigned sigh. "I am beginning to fear that—eep!" She jumped as Pokey Pierce appeared on the stairs behind her.
"You all need to get to the throne room right now," he said urgently.
"What? Are you crazy?" said Pinkie. "We might maybe sneak the rest of the way down the stairs, but then we'd have to sneak across open grass to the back door of the palace, and sneak up the stairs, and sneak in the door! There's no way we can do all that sneaking without getting seen. Believe me, I know sneaking!"
"I know. But Dale said that Twilight Sparkle was there. And he said you have to get there as soon as you can. I think..." He paused, glancing over and gauging the distance. "I've got the spell down now, I think I can wink there carrying one of you. I'm not sure I can do it four times, but I'll try."
"I can wink too," spoke up Rarity. "I am not terribly expert at it, I've barely winked since school." She smiled then, a little bitterly, and said, "I have carried my dear departed Opal a few times, however, and I think that just now Fluttershy and I together weigh no more than Opal and I did then. I can carry her."
Pokey relaxed a bit. "I can do it if I only have to make two trips."
"Then what are we waiting for, darling? After you." Rarity gave him an elegant nod. Pokey smiled at her, blushing just a bit, then turned to Pinkie. His horn glowed. He strained and it brightened, gaining a second corona. Then, with a soft bang, he and Pinkie vanished from the downward stairway and appeared at the top of the one that led to the back door of the palace.
Rarity took a moment longer to gather her magic, but she too made the trip, with Fluttershy beside her. She staggered when she arrived, nearly going to her knees. Her smile was triumphant despite her weakness, though. It had taken every ounce of magic she had, but she'd done it.
Pokey looked exhausted, but he vanished from the top of the stairs and reappeared next to Applejack. Then they too were atop the stairs. Pokey collapsed completely, lying prostrated on the stone, his horn smoking slightly. "I will never move again," he mumbled.
"Maybe you'd better—here come some Shadowbolts," said Pinkie.
Applejack hadn't wasted any time, she'd already opened the door. "Servant's hall here, looks like. Let's hustle, we gotta find the throne room and Twilight, quick!"
She darted inside. Pinkie followed. Rarity and Fluttershy, however, moved more slowly. Rarity in particular was barely on her feet. A dark form swooped through the air towards the stumbling unicorn. Applejack started to shout a useless warning.
Suddenly there was a deep, booming sound and a wave of shimmering fire flashed across the sky. It tumbled the Shadowbolts from the air, grounding many and scattering the rest far and wide.
"That was a rainboom!" said Rarity in delight. Her already dreadful mane was now completely blown askew, but she could not even bring herself to care.
"Dashie!" said Pinkie, bouncing with glee.
"Well if Rainbow Dash is on 'er way, we'd better hustle ourselves!" said Applejack. "Here, I'll lend ya a hoof," she said to Rarity, and the next thing Rarity knew she was lying across Applejack's back as the strong farm mare cantered down the hallway.
Pinkie grabbed Fluttershy similarly and ran after her. "We're coming, Twilight!" she shouted gleefully. "We're coming to take down Black Snooty forever!"
Twilight's heart leaped in her chest. In front of her she saw the swiftly growing ember that had to be Spitfire and Rainbow Dash. And now, behind her, she heard the faint echo of a voice that was surely Pinkie's, along with the sound of hoofsteps echoing off the stone walls. Her friends were coming for her.
Her friends that had been with her through so much darkness and pain. Her friends that had fought, and suffered, and somehow stayed true to everything they were, even in the worst of times. Her friends that she had known and loved not merely for one single festival day, but for weeks of toil and hardship.
The spark that shone in her eyes was stronger than ever before, as was the magic that began to pour into her. Even as Spitfire, carrying Rainbow Dash and trailing a long arc of literal flames behind her crashed through the window and into the throne room, even as Applejack with Rarity, and Pinkie Pie with Fluttershy came running out from a little door tucked behind the throne, and even as Nightmare Moon looked around in confusion and disbelief, Twilight's eyes began to glow, the magic of harmony filling her to the brim.
"What?! No, this cannot be!" screamed Nightmare Moon. "That magic cannot be! I destroyed the Elements!"
"No you didn't," said Twilight. She was rising into the air. She closed her eyes, not needing to see to know that her friends were being drawn to her, rising around her. "You destroyed a few pieces of rock. The real Elements of Harmony cannot be destroyed, not as long as laughter, loyalty, honesty, kindness, generosity, and friendship still exist in the hearts of ponies."
"No!" cried Nightmare Moon, but she had no time to say anything else, for Twilight opened her eyes, and the light blazing out from them was one with the rainbow that curled around all six ponies and shot out at the Nightmare, wiping her darkness away.