Adventure Hook by Chris Reese
A group of scholars, protected by the heroes, enter an ancient tomb with the inside covered under a thick layer of dust. The dust is everywhere: the ground, the walls, the statues, the hieroglyphs, and on the scrolls.
One scholar picks up a scroll and begins to read about the nightmare horror known as Quachil Uttaus, the Treader of Dust. Struck by terror the scholars want to leave immediately but the tomb is suddenly closed shut — even the outline of the door has vanished. The heroes hear a rustling in the back … now they must solve the mysteries of the Long Forgotten Tomb or suffer the wrath of Quachil Uttaus as the Old One hunts them down.