A white horse dies

Vix was standing in a field.
To his left stood a red barn. It looked as if it had just been painted, and was in good shape, even if this kind of barn most definitely must have been built long ago.
The barn was surrounded by green fields as far as he could see, and to his right a horse was drinking out of a wooden trough. The horse was light grey with small black-patches all over and a long ragged mane. He seemed like a kind of working horse rather than a show horse or something fancy.
But he seemed like a good horse, Vix thought.
Suddenly, out of nowhere, a person came riding towards him on a tall black horse.
He was dressed in full plate armour, and was holding a long sword in each hand, and at first Vix didn’t recognize him, but as he came closer he could see that it was his friend from the living prison he’d once been trapped inside.
Vix tried to wave and make himself noticed, but his friend ignored him and instead rode straight towards the white horse and decapitated it in one movement.
As Vix stood speechless, the blood started gushing out of the headless body and into the water-tray and the surrounding ground, as if its life-juices returned to their origin of water and earth.
His friend rode towards him holding the horse’s head by its blood-stained mane, his two swords dripping with blood in the other hand.
"What the hell are you doing?" Vix shouted, with tears in his eyes. "He seemed like a nice horse."
His friend just stared blankly back at him, like his savage actions meant nothing at all – almost as though he hadn't even noticed what he’d just done.
Then, a sense of panic grew inside Vix, and he said to his friend:
"We have to get rid of this head. And you have to clean your bloody swords. Otherwise we'll be in deep trouble when they return."
Vix didn't know why, but he had a strong feeling someone would be returning soon, and that they would be in deep trouble when they eventually did.
"That's fine", his friend said.