Something moved in the shadows. What was it? The black shape munching the grass by the river's edge. The boy wondered how it got there without him noticing, as if appearing out of the mist.
He ventured a little closer, watching the shape closely. Steam billowed out its nostrils as regular as the river lapping the stones beside it. It was enjoying the feast and the cool night air.
The boy leapt at it with a rope and tried to throw it round its neck. The creature, startled, stood and let him. "Aha!", the boy thought triumphantly, "You'll make a fine work horse!"
He thought of how his Daddy would praise him for finding such a good animal to work on the farm. His Mammy would rub his head and make him some porridge and -
The creature bucked. She rose up on his hind legs and snorted. The boy let go of the rope and the creature stopped and stood still, staring with black eyes at the boy, snorting a warning. Reaching for the rope again caused the same reaction, with the creature only stopping when the rope was released. Three times the boy made his clumsy attempts.
Then the creature ran out of patience and when the boy grabbed the rope again she pulled him in the direction of the river. The boy shouted and tried to let go, but the rope was wrapped around his arm, binding him tightly to the creature.
The river-horse dived down. Deep down to her home under the water.
And soon, so soon, the ripples settled on the brackish water. Settled into its usual pattern against the rocks and reeds atop the bottomless blackness.