The Hidden Chamber

This is my very first attempt at DMing a game. I've been playing the game all these years, but only as a pawn in a friend's game. Now I'm going to be in control, and it is going to be awesome. I might have to work out some kinks, but I know my experience as a player, and creative writer, will lend itself well to this first shot at Game Mastery.

The Concept, you and 3-4 other players are servants of some kind to the recently fallen King. A royal rival has come, is in the midst of destroying the vast castle you reside in and finding the princess to steal as his bride. He has killed your King, stabbed him while you were in the King's chamber. Wounded and dying, he had you all go into his escape tunnel behind his throne. You are unknown to the enemy, and that's where and when the game will start.