The Ninja Epidemic

You step back and look around. You don't see any ninjas hiding behind rock and shrubs. Nothing behind the trees, and no one retreating from the woods.

Then you look up and see them, standing on the braches of the trees like so many black crow awaiting the opportunity to strike down and devour the carcass which you will most likely soon be.

You hear the ninja you had spotted in the distance charging towards you recklessly from behind.