in the corner of your eye. . . / short story

Four campers, planning to stay just two days in their local forest. One day, while roasting marshmallows and telling stories at the campfire, one of the campers noticed something flash by in the corner of the person's eye. . .
One camper lost.
Another.
Another one.
The last one seemed to be spared. . .
or so that camper thought. . .
until he saw it again. . .
in the corner of his eye.