Equal Rites by Terry Pratchett

before.
    Granny looked over the valleys stretching out before them until she found what she was after. A gray eagle was circling lazily over a distant blue-hazed patch of forest. Its mind was currently at ease. It would do nicely.
    She Called it gently, and it began to circle toward them.
    “The first thing to remember about Borrowing is that you must be comfortable and somewhere safe,” she said, smoothing out the grass behind her. “Bed’s best.”
    “But what is Borrowing?”
    “Lie down and hold my hand. Do you see the eagle up there?”
    Esk squinted into the dark, hot sky.
    There were… two doll figures on the grass below as she pivoted on the wind…
    She could feel the whip and wire of the air through herfeathers. Because the eagle was not hunting, but simply enjoying the feel of the sun on its wings, the land below was a mere unimportant shape. But the air, the air was a complex, changing three-dimensional thing , an interlocked pattern of spirals and curves that stretched away into the distance, a switchback of currents built around thermal pillars. She…
    …felt a gentle pressure restraining her.
    “The next thing to remember,” said Granny’s voice, very close, “is not to upset the owner. If you let it know you’re there it’ll either fight you or panic, and you won’t stand a chance either way. It’s had a lifetime of being an eagle, and you haven’t.”
    Esk said nothing.
    “You’re not frightened, are you?” said Granny. “It can take you that way the first time, and—”
    “I’m not frightened,” said Esk, and “How do I control it?”
    “You don’t. Not yet. Anyway, controlling a truly wild creature isn’t easily learned. You have to—sort of suggest to it that it might feel inclined to do things. With a tame animal, of course, it’s all different. But you can’t make any creature do anything that is totally against its nature. Now try and find the eagle’s mind.”
    Esk could sense Granny as a diffuse silver cloud at the back of her own mind. After some searching she found the eagle. She almost missed it. Its mind was small, sharp and purple, like an arrowhead. It was concentrating entirely on flying, and took no notice of her.
    “Good,” said Granny approvingly. “We’re not going to go far. If you want to make it turn, you must—”
    “Yes, yes,” said Esk. She flexed her fingers, wherever they were, and the bird leaned against the air and turned.
    “Very good,” said Granny, taken aback. “How did you do that?”
    “I—don’t know. It just seemed obvious.”
    “Hmph.” Granny gently tested the tiny eagle mind. It wasstill totally oblivious of its passengers. She was genuinely impressed, a very rare occurrence.
    They floated over the mountain, while Esk excitedly explored the eagle’s senses. Granny’s voice droned through her consciousness, giving instructions and guidance and warnings. She listened with half an ear. It sounded far too complicated. Why couldn’t she take over the eagle’s mind? It wouldn’t hurt it.
    She could see how to do it, it was just a knack, like snapping your fingers—which in fact she had never managed to achieve—and then she’d be able to experience flying for real, not at second hand.
    Then she could—
    “Don’t,” said Granny calmly. “No good will come of it.”
    “What?”
    “Do you really think you’re the first, my girl? Do you think we haven’t all thought what a fine thing it would be, to take on another body and tread the wind or breathe the water? And do you really think it would be as easy as that?”
    Esk glowered at her.
    “No need to look like that,” said Granny. “You’ll thank me one day. Don’t you start playing around before you know what you’re about, eh? Before you get up to tricks you’ve got to learn what to do if things go wrong. Don’t try to walk before you can run.”
    “I can feel how to do it, Granny.”
    “That’s as maybe. It’s harder than it seems, is Borrowing,