This is one of the coolest adventure intros I've ever heard of. I have not used it, nor was I so privileged to have been present when it was used.
"You are fixed firmly in the goings-on of your normal, routine life (however routine, or not-so-routine it may be), when suddenly you are unfixed. Literally! Yes, you find yourself floating, for lack of better descriptive terms, your mind a blurry mish-mash of random thoughts and memories, nauseating colors, and dizzying mists. Just as you expect to blank out you begin to recover, the blurriness fading, colors melting, your mind returning. Your surroundings, however, have changed. You look about, finding yourself in an unusually dark room seated at a table along with X other people. All of them seem as bewildered and confused as yourself. Before you can speak you are spoken to. A resonating voice rings forth:
'You have been summoned.' "
At this point the Dungeon master should describe himself - yes his/her actual self - to the party as fading into view before the table where it is revealed that the DM is summoning the party members to accomplish some task. Go to Comment
The PCs are setting up camp at the end of their first day of walking through the Esh-Inel Mountains, when they hear in the distance a low rumbling, like thunder. It grows progressively louder until it echoes off the mountainous bowls around them, then dies away again. At its worst the ground starts trembling. It happens every day at this time, and it is the noise of the Great Carts on the dwarfish underways returning home after a day mining, laden with many tons of ore.