Bob jogged in place for a few steps, just enough to get his heart rate up. Thinking about his big presentation this afternoon made him nervous and excited at the same time. He had to work some of this energy off.
He swung one fist straight out and then another. After a few times he got into a rhythm, which was when he noticed the shadow cast by his desk lamp. Shortening his swings he stepped closer to the wall and then in a burst of impulse actually punched the wall, right where in his shadow's jaw.
"Ow!"
He jumped back in surprise at the yelp.
"Hello?"
There was no answer but another punch brought another answering cry.
"Who is that?" said Bob.
"Can't you see? Your shadow, you idiot."
Bob stared with his mouth gaping open.
"My shadow?" he finally asked.
"Yes dammit. I'm not supposed to talk. None of us are supposed to talk. But I wasn't expecting that. Why the fuck did you hit me?"
"Haven't you ever heard of shadow boxing?"