As Twilight watched her friend be drained of her energy, she kept calling her name, trying to revive her. It was no use though. Rainbow Dash had slipped into a deep sleep fueled by magic beyond her control. All she could do was wait. Wait for the rest of the girls to catch up.
And so she did. She waited for what seemed like hours until finally, the group caught up with Fluttershy and Applejack carrying the sleeping form of Rarity on a makeshift hammock while Pinkie bounced along behind humming a song that was unfamiliar to everyone.
"Sorry Twilight, but after seein' the gorge light up brighter than Canterlot on Hearthswarming eve, we couldn't wait for you any longer," said Applejack through gritted teeth. Her and Fluttershy put Rarity down and took a huge breath. "Oh no. What's happened to Rainbow?!" she said after noticing her friend propped against a rock a little ways away. She went to Rainbow as soon as the sentence left her mouth.
As she approached her friend, she noticed Rainbow in a terrible condition. The color from her mane and coat had darkened, and she had bags under her eyes. Her element had also changed. The crystal in the center was gray, and the gold rim had changed to silver. Heat could be felt radiating from her body 3 feet away, signifying that she was terribly sick. She had short, wheezing breaths. Tears came into Applejack's eyes as she frantically aksed Twilight, "What's wrong with her? Why is she so sick?"
"I think she just used too much energy. When I say too much, I mean enough energy to power Ponyville for a couple of hours, which is suprisingly more than some ponies think. If we can get her to a hospital, they might be able to help her." At the mention of a hospital, Fluttershy became shaken and Pinkie's mane deflated, bringing with it a frown. "I sure she'll be fine, but the sooner we get her there, the sooner she'll be better. Fluttershy, could you fly up and grab a small cloud? We'll need it to transport Rainbow Dash back to town."
"Oh, um, sure Twilight," mumbled Fluttershy. She flew up high and within a minute, she had returned with a cloud that looked like a giant pillow, if a bit more poofy.
"That's perfect. Thank you." Twilight then levitated the sleeping Dash onto the cloud, and began moving it with her magic. Pinkie Pie took over Fluttershy's job of supporting Rarity while Applejack picked up the other end, her mind on her two friends who were now incapactitated.
Twilight began to search Dash's aura and physical status with her magic. She was in much worse shape than she looked. There was muscle damage throughout her entire body, mostly in her right forearm and chest. She had major blood loss, which Twilight assumed had been used as a source of energy for when Rainbow's stock ran out, and her aura was faded. Then, Twilight noticed something else; a dark presence in Rainbow Dash's soul. She had the worst feeling that she had sensed the presence in somepony else, but she couldn't quite put her hoof on it. Wait, no, that can't be right. Twilight could SEE Rainbow Dash's aura. She had never heard of anything like it. Come to think of it, Rainbow did it earlier, but she could see all 4 of the the other pony's auras, even her own and Rarity's unconscious and fading one. This boggled her and left her with even more questions for Dash when she woke up. If she wakes up, she thought to herself. Gaining a new sense of urgency from Dash's actuall condition, she flew off toward Ponyville at top speed. She flashed a telepathic message to the others, telling them of her need to get Dash to the hospital sooner. They understood, and kept carrying Rarity toward town through the bottom of the Ravine.
Upon arriving back in town, Rainbow Dash's condition was already much worse. Her muscles seemed to be failing completely, and her breathing had become very shallow. If Twilight knew better, she would understand that Rainbow Dash was on the verge of death. She had used so much energy that it had effected her very soul. Racing to the hospital, Twilight made one final scan of Raibow Dash. What she found disturbed her to no end. The dark aura inside of Rainbow had begun to take over. It was now trying to crush Rainbow's soul and replace it with its own. Twilight yelled for help, but no one seemed to care. They were all to focused on the nearby shops to notice what was happening. And even if they did pay attention to Twilight's cries, they couldn't see what was really happening to Rainbow Dash. Twilight had to get her to the hospital, but she also had to stop the dark aura before it crushed Rainbow's soul.
As if in answer to an unspoken prair, the Wonderbolts landed next to Twilight, told her to jump on the cloud, and carried her and Dash toward the hospital in a flash. "Spitfire, why would you help us?" asked Twilight, a bit bewildered that the Wonderbolts where flying her and Dash.
"What, do you think we'd just leave the pony who saved our lives like this? We'll be at the hospital shortly. Focus on helping Rainbow Dash while we get you there."
"Okay. Thank you Spitfire. Make sure that you tell the nurses to keep me close to Rainbow Dash at all times."
"Will do. Now, go help your friend." Feeling reinvigorated by the Wonderbolt's words, she dove headfirst into Rainbow's soul, falling unconcious herself, to help her stop this dark aura.