Dungeon/Castle Tile, 2" x 3", Trap Door, 2x2

Along the corridor you spot a wooden trap door set in the floor.  As the party debates whether or not to open it, backs turned, a violet mist rises from around the gaps in the wood to silently sweep further down the passage.

Trap door, dual-sided tile, plain on the other side.  Random textures, cracks, and colours.