Prompt: Write a short story about a man who discovers a magical portal

Roy was just an average guy, until one day when he discovered a strange portal. After stepping through, he found himself in a strange world full of creatures of all shapes and sizes. He was quickly captured by a group of goblins and taken to their leader, King Goblin. The goblin king was incredibly cruel, and was only interested in using Roy for his magical abilities. Roy refused to be used and fought back, eventually escaping and returning home. Roy never forgot the portal or the world he had discovered, and often dreamt of returning to see it again.