Giant spiders fleeing from Bilbo as he wields his sword Sting in Mirkwood.

But at last, just when Bilbo felt that he could not lift his hand for a single stroke more, the spiders suddenly gave it up, and followed them no more, but went back disappointed to their dark colony. The dwarves then noticed that they had come to the edge of a ring where elf fires had been. Whether it was one of those they had seen the night before, they could not tell. But it seemed that some good magic lingered in such spots, which the spiders did not like. At any rate here the light was greener, and the boughs less thick and threatening, and they had a chance to rest and draw breath.

~ The Hobbit or There and Back Again | John Ronald Reuel Tolkien ~