Worse Things Waiting — Brian McNaughton

Martin scrambled for the flashlight, turned it directly on the old man.

And saw the flies.

The man was covered from head to foot with a squirming mass that glittered blue and black and green in the beam of his light. Fighting back his revulsion, Martin ran to the man's side and tried to bat the insects away, forcing himself to plunge his hand in and brush the flies from the old man's face. The swarm exploded, momentarily blinding him. He spat and snorted and retched as he felt strays crawling in his mouth and nostrils.

When he groped for the man's face, his fingers touched only bare floorboards.