The strange pony.

Why can't she let me be?! She doesn't understand. They mean well, but I can't stay. I don't want to hurt them. I need to get back; Then I can-

"Stop! Please!" Rainbow Dash shouted.

"No! Leave me alone!" She replied.

"Please! We can help." Rainbow was flying close to the rooftops, and Rainbow was struggling to not hit anything.

"No, you can't!" She was running on the rooftops, as fast as she could towards the Everfree. She gritted her teeth against the wind. A flash of red covered her naturally green eyes, then vanished in a grimace of fear as she crashed into Sugarcube Corner. She got up, opened her now green eyes and shook herself off. She jumped down, and booked it for the forest. Rainbow was right behind her.  Rainbow got dust in her eyes and mouth. She kept on going. The mare howled, and responding howls echoed back.

"Let me be! You CAN'T help me! Haven't I made that clear?!" The mare said.

"We need a better look at you. Make sure that you're not too hurt, so, no." Rainbow replied.

"I'm not hurt, Rainbow. I just don't want to hurt you." The mare said. A huge wind blew Rainbow back and onto the ground. Applejack caught up. The mare stopped right outside of the Everfree. A dart blasted past the three, and the stallions that Rainbow had saw yesterday were running towards the mare. She flew. Rainbow flew after, and Applejack ran back to the castle. Why, she didn't know. Maybe the look that the mare had in her now blue eyes. It was anger.

For some reason, they were heading towards Canterlot. The mare looked at Rainbow with blue eyes, seeing trailing behind. She flapped faster. So did Rainbow.

"Why won't you leave me alone?!" The mare whispered. Rainbow could hear her clearly, although wind was rushing past her ears.

"I need to know why you're here, howling at the Timberwolves. And why you're running from the stallions in green." Rainbow replied. She thought a bit. "What's your name?" Rainbow asked.

"Will you ever leave me alone?" The mare asked, frustrated. They both hovered in midair.

"No. I wanna know who you are. I wanna be your friend." Rainbow replied. Oh, just get it over with. I'm wasting time with her. I need to get to the Princesses. At that, she smiled. She swooped down, then flapped even faster to the castle. Rainbow wondered why she was running, or flying away from her friendship. She flapped after her.

Meanwhile

"Doctor, we lost her. This blue pegasus mare swooped off with her to the town."

"And then she flew away to the Princess."

"She WHAT?! I'll deal with this. You may go. Thank you."

"Yes, sir - err - doctor. Will do." They trotted off.

"Celestia, please bring her back." He looked at the blue vial in front of her as he said that, then sighed and went back to work.