The Secret Door of the Mountain

The king had always been fond of gold, right? And now, the way he saw it, he had a golden opportunity to expand his collection. So one night while everyone in the palace was asleep, he secretly made a decision. The door of this mountain will only stay open for fifteen minutes, a quarter of an hour. If you're not out by then, you will be trapped inside. Do you understand? He nodded, then raced into the mountain, his golden robes flying out behind him. For the moment he stepped foot outside the mountain, the distant clocks struck twelve and the secret door slammed shut behind him.