And at year’s end they broke the stable door
The man and horse, together, gallop yet
Beyond the sunset’s end, the pounding hoofs,
Both harmony and beat for their duet.
Jo Walton.
This little poem appears in Among Others, and I wrote it when I was a teenager, I’m not sure exactly when, sometime before 1982. That story is about the shape of the possible. I always want to give the possible the widest possible answer space — it makes me happy to think that the horse will learn to sing.