The party creeps down the stairs which end at a 40 foot square room with a 10 foot tall ceiling. As there seems to be no people or creatures in the room, the party steps through the doorway. A breeze blows into the room from a 10 foot wide open passage in the far (west) wall, directly across from the stairs.
Two 4 foot diameter circular doors are set into the middle of the south wall. Each is made of wood and framed by a ring of mortared stones. Of these two doors, the one on the west is closed and inscribed with a strange glyph or rune at its center. The door on the east bears a different glyph and is half-open, revealing an iron rim of gearlike teeth around the circular wood of the door. Dim light spills from the chamber beyond.
Mounted to the walls of the room are twelve tarnished copper masks. The masks are 2 feet tall and cling 4 feet above the floor, and are placed at intervals circling the room, wherever there is not a passage or a door. Each one depicts a smiling gnome's visage. The soft giggling, chirping, and rustling noises seem to pour from the very walls.
Don't forget to refer to your map occasionally. Let me know what each of the party is doing, and examine the room or make a decision on which path to take as you will.