A single day up the road from Khedia, the party camps for the night, and awakens in the morning in a new place.  This isn't where they stopped to sleep, and none of the sentries posted noticed the change until they were waking, along with all of the rest of the group.

Your sleep was plagued with nightmares, and when the sun rises you all look out on a world gone mad.  Instead of the site where you had camped last night, your bedrolls, mounts, and pack animals are now in a foyer of an ornate mansion.  A freshly swept carpet graces the floor.  The walls are decorated with bright, colorful tapestries.  Brass candelabras line the entranceway.  They show the signs of having been recently polished and are filled with candles.

More frightening that the sudden change from the wilderness to a mansion, is the smoky gray mist which surrounds the mansion at a distance of 30 feet, blocking all sight beyond.  No sound penetrates the mist.  One pack animal pushes through the outer doors and wanders into the mist, quickly disappearing from sight, but its lead rope remains, still, on the ground.  Moments later, when the rope is pulled back in, the animal's dead body is pulled back into the sunlight.  What killed it cannot be determined, but it died with a horrible look of pain on its face.  The mist advances on you even as you watch, but luckily it does not enter the foyer.  The double doors to the interior swing open into the main hallway by themselves.

Elboc quickly shuts the outer doors to keep the mist out.

"Are our treasures still here?" asks Elboc, raising the most important question.

Roak rubs the eyes from his sleep and stands up. "What the..." he shouts and immediately checks his bags for his gems!!

As Elboc says, first things first.

Hamburg's life prior to the party's emergence into the glorious surface world had been filled with odd and sudden changes to his situation and surroundings. He only found this odd because it was not accompanied by the pleasant euphoria he was accustomed to, brought on by the powerful mushrooms his people regularly consumed.

"Looks as if we've been invited!" he said cheerfully, and took a step toward the double doors. "Perhaps they've been expecting us for dinner. 'Twould be rude to keep them waiting..." He continued forward through the doors.

Elboc and Roak quickly look around and satisfy themselves that all of their treasure and recent acquisitions are present.  The pack animals are obviously quite nervous, and the mist swirls a bare few feet from the walls of the building, but the day outside looks to be otherwise sunny and bright.

The parted inner doors show a long hallway with another set of double doors at its far end.  Tall, narrow windows appear on the left-hand wall of the hallway, and a single door stands, closed, in the middle of the right-hand wall.