This started out as a piece of fantasy fiction.
He watched as the raven pecked hard at something with its long sharp beak. Wondering if that was where the word ravenous originated, he walked over to the blackbird, waving his arms like a bird taking flight and shouting loudly. The raven gave him barely a glance and puffed its feathers up, hopping for a moment before finally taking to the air and fleeing the scene. There, on the ground where the raven had pecked voraciously, lay a dead bird. A sparrow, horribly mutilated and gouged.
Crouching, he stared at the dead bird and glanced around before finally giving in to his morbid compulsion and fingered the cadaver. It felt soft and under his probing finger things began to writhe in its corpulent belly. His finger pushed harder and the sack of flesh slowly crumpled, its stomach issuing forth its hideous cargo of maggots.
For a moment he was still, his eyes watching the white larvae as they crawled hither and thither. And then, it came to his face, that most innocent of acts. A childish smile.
His mouth made a sound without his mind directing it. It sounded like a snigger. He looked around, scrutinizing his surroundings but there was no one about.
He was alone.
For a moment, he considered what he should do but finally thought better of scooping up the dead creature and stuffing it into his mouth. Especially in public where anyone could see.
Swallowing hard, he buried his head in his hands. Closing his eyes, he began to wish those thoughts away. They were wrong and he knew it; he made himself believe it, at least. Silhouetted on his eyelids was a picture of the bird, the specks of whiteness creeping across in all directions were the maggots, he realised.
Slowly standing up, he reached into his pockets and withdrew the pack of tablets they had given him. He swallowed again, opened his eyes and popped two of the red and white capsules in his mouth. But then spat them out onto the ground as he felt them writhe in his mouth. Looking down he saw them surrounded by the maggots.
His stomach finally began to heave with the utter sickness of it all and he turned and ran.