This is the beginning of the story.
Farsight heard the beads on her curtains clack against each other, and looked up and saw Prince Blueblood duck through them into the dimly-lit back room of the magic shop. She nodded slightly to the prince, then returned her gaze to the crystal ball placed in the center of the small wooden table, taking deep, regular breaths as she began entering her trance.
The old earth pony had no magic that unicorns understood, but she had something else, something much less common, which was why even a prince of Canterlot might risk his reputation to consult her.
"Sit," she said, without looking at him. "Listen."
She gazed deeply into the ball—not that the ball mattered; it was merely there to prevent her from looking quite so mad while she stared into nothing, and to keep the clients from distracting her with their insistent gaze. She felt for the connections, the tendrils of fate slithering on their way from past to future, and reached out to touch Blueblood's bright lifeline. She felt her way up it, forward into the future.
She gasped. There was someone else there, in the future, traversing this same line in the other direction. She tried to draw back but could not. She felt her mind locked in an iron grip, which pulled her down and under the stream of fate, forward in time and far away from her body.
What have we here? she heard a voice say, and felt scaly claws rummaging through her mind. It seems we share an interest in the good prince. How convenient. You just go to sleep like a good little pony and I'll take over from here. Why, I'll tell him the truth—it will make it that much more delicious when he sees what it means.
She tried to scream, to lash out with her feet, but she could see nothing, hear nothing, and feel nothing but the chill, foul fingers picking over her memories.
You're a fighter, for an old hag, the voice said. Nice try. I'll give you a seven point five for effort. You're going to be very helpful to me, Miss Farsight. I'll let you live, when I reclaim my throne. Maybe even as a pony.