Sally was sitting on the sofa staring intently at the large cardboard box in front of her. Suddenly, it started moving like there was something very big and nasty inside trying to get out. Whatever is it was she could hear it clawing at the box in a desperate attempt to escape.

After a couple of minutes, Sally had decided that enough was enough. She knelt down in front of the box and then very slowly, very cautiously removed the lid.

She looked inside.

The box was empty.