Sherlock Holmes and Doctor Watson are hiking. They hiked all day long and then, having gotten tired, unpacked and quickly retired.
Holmes wakes up deep into the night, wakes Watson and says "Watson, do you see the bright stars and do you notice how clear the sky is? What can you deduce from it?"
Watson yawns and tries to play the game. "Well, this clearly tells us the weather tomorrow is going to be dry and sunny."
"No, my friend. It's much simpler than that. Someone has stolen our tent."