In the dawn of Equestria's brilliant sun, Shimmering Dusk woke up in a field of apples. How was she home? Had her punishment ended? She didn't know. All she knew is she had a splitting headache and a hatred for the sun. The last thing she could remember was drowning and now she's here.
With a wonder in her hoof beat, she clopped through the orchard. The thought hit her, I'll fly and figure out where I am. So she flew into the air as her wings seemed tired and aching. Pushing them through the pain, Dusk saw the landscape. Ponyville was ahead of her, Zecora just past that. Although she saw something strange, fires and smoke rose from the town in billows.
Exerting all of her strength left, she flew speedily to Ponyville to find Zecora in town giving healing aid to those who needed it. Her joy knew no bounds as she ran to Zecora, "Zecora! Zecora I'm back."
Zecora's tired face lit up with some joy, "That you are I see, but banishment was canceled or you simply roam free."
"In a way, I went to the ancients for guidance. I got it. I was punished for my crimes and sent back by the ancient magic of the elder princess' of long past. I knew it was the better way," Dusk spoke knowingly as she looking around confused, "What happened here? It's almost all destroyed."
Zecora's lost look seemed tinged with fear, "A new danger Ponyville may have now, Twilight and her friends are away I know not how. A bat-like pony enflamed the town and now these ponies' worlds are upside down."
Dusk just nodded adamantly, "I will stop them. Whoever is attacking this town, they will be brought to justice or else I'm not the protector my cutie mark says I am. Let me do this with your help Zecora. I need you to help the towns ponies get better. I'll try to investigate the damage."
"Be careful, Dusk. This path may yet bring up a past you may not want to musk," Zecora said as she went back to helping ponies.
Dusk nodded in agreement as she ran and looked for signs. Each house nearer to this large tree was more and more damaged. She found hoof prints leading to the forest as following them was her only lead. So following hoof prints she went until she stopped at a cave. It was decorated in torches and different pieces of equipment that were meant for damage. This had to be stopped and soon, she thought.
A hoof caught my shoulder as she spun around on the defense, "Hey!"
A purple pony with wings and a unicorn horn stood in front of her. Twilight Sparkle is here now, she thought, well I'm banished to the nether realm. Twilight's voice was stern and collected, "You were supposed to stay banished, Dusk. How'd you get here? How did you leave the Elder Magic realm."
"I was there until my punishment was through. Thus it is done by the Elder Princesses long past. So I am free to be here. As for here, I'm investigating why Zecora's friends were hurt. She's a dear friend to me and I can't see her lost and sleepless like that," Dusk spoke with determination in her voice. She knew they could not refute the old law.
Twilight just nodded in agreement, "If you were let out of there for good reason, I won't dispute it. It seems our goals are the same though, so we should work together to stop this."
Dusk raised one hoof, "One rule, no magic used on me. I won't have it anymore, deal?"
"I… I can't guarantee that. Just… Fine," Twilight shook a hoof on it, "No sneaky business now though."
Dusk just thought of something as her anger grew, "Wait you were gone with the elements of harmony… You lied to them. Zecora thinks you're off saving another place and you're here. How could you?!"
"Well…" Twilight kicked some dirt absently, "We needed to lie so that our enemy would come out. We tried to purify it but it didn't work. It's like it was missing the reason and sanity from its mind."
Dusk just thought of something and walked from the cave to a nearby shrine hidden from view. She moved a few stones and kicked the symbol of a black and white pony staring at each other, "More likely than not, the enemy is only half of itself. Without the other half, purifying is useless. So we should find-"
Dusk turned around to see Twilight was unconscious being flown off by some pony in black and red with bat wings. Zecora was right, she thought, bat-like pony indeed. She took off and flew after the batpony at full speed. Pushing each wing flap faster, she found herself increasing faster than she could before. Rainbow Dash was pulling her as fast as she could as Dash threw Dusk towards Twilight.
With the added speed, I flew into the batpony at top speed in a mess of hooves. My hoof stuck to hers as the batpony seemed scared. Her scared and fearful cry as I absorbed her without thinking were just heart breaking. Dusk fell to her side trying to remember the darker side's destruction and plans. It was upsetting as she blocked her control and slowly took over the body as best I could.
Dash caught Twilight as Twilight stood dizzily. Twilight turned to see Dusk on the ground unmoving, "Dusk! Wake up. You need to wake up…"
Dusk's unresponsive pony body lay there without any breathing or movement. Twilight only stopped and focused on her magic as she entered Dusk's mind. Twilight thought, I'm sorry but I'm not letting you get away with going away before I can thank you properly.
In Dusk's head, the world was black with memories flashing by at miles a second. Twilight dug through them and found the one that mattered, the darker side. She pulled it with her in a magic bubble spell to hold it. Twilight continued into the mind to find a small filly crying as others mocked her color and inability to fly. Twilight knew it was Dusk as she put a hoof on her shoulder, "Hey. We should go. You're not meant to be here. I want to show you something."
The small filly looked up, "Are you sure? You won't mock me either?"
Twilight simply nodded as she led the filly to a memory where Dusk had gotten her cutie mark. The filly watched as her older-self had fought off a pack of timber wolves from going after a pony. When the fight was won, Dusk's older-self had been hurt but then something amazing happened. A white circle with a shield and sword appeared on her side as she stared in wonder. The filly just smiled, "I become a good person don't I? Do you help me become a better person?"
Twilight shook her head no, "I helped banish you and I'm sorry. You were right that day, you couldn't have made those deliveries. If you can, both of you, forgive me."
The darker mare stood beside Dusk as the filly looked up at the darker mare. The filly smiled as the darker mare had looked down upset with herself. The filly smiled and disappeared as the darker mare became Dusk in her current state, "I'm sorry… I snapped and all I could do was defend myself, like I had done for my friends back when I had them so long ago."
"You're fine. We should have become better friends. I know we will now though," Twilight smiled with a bright look.
Dusk just nodded, "I accept the apology and I'm glad you came. You tried to understand me, even through my anger. I'm sorry and I hope its better. But if you don't mind, I'm tired. I haven't slept at all in months or years anymore."
Twilight nodded as she sat and fell asleep as a bliss as magic covered her mind. Twilight woke up outside again as Dash still stood there. Twilight just nodded with a smile, "She'll be okay. Just needs some rest a good set of friends. I think I know where to find that."
Dash just agreed as she carried Dusk back to Ponyville. Twilight knew Dusk would help rebuild and would balance herself out again, but only with the help of friends.