A Kingdom Kidnapped

Story You are a king of a distant, fictional land who wakes up one morning to find that everyone has disappeared. Your family, guards, citizens, even the citizens pets. You exit the castle to find a note that reveals that a soldier you had imprisoned many years ago has been holding a grudge against you for all those years and learned dark magic to make you pay for what you had done. He finally escaped and cast a spell on the entire kingdom leaving you to come rescue them yourself. I mean what is...