You've got to run a generic fantasy roleplaying game, somewhat open-ended, in fifteen minutes.
You think of your favourite books, most beloved movies, nostalgia-inducing memories of past games.
What's your favourite fantasy-themed starting situation for an adventure?
Double points if it's easy enough to explain in a paragraph, and doesn't require background knowledge of anything else.
Young homeowner living a peaceful life discovers that his uncle has left him an heirloom which, unbeknowst to him, is an item of great age and power. The item belongs to a Dark Lord, who needs it to reign over all the world. Supernaturally-frightening creatures - servants of this Dark Lord - from a distant land are on their way to claim it at this very moment!
...and they can sense its presence, no matter where it goes!
(Lord of the Rings; you play the young homeowner and/or his traveling companions)