Next we turn to The Paraelemental Plane of Smoke. From the Planescape Campaign Set we have the following snippet:
Little traveled and less known, the paraplane of Smoke lies between the
planes of Air and Fire. It is groundless like Air and hot like Fire,
though it doesn’t scorch. The air is filled with rolling clouds of
choking smoke, foul with brimstone and gases, so it’s impossible to
breath safely without aid. Toward the plane of Air the poisons clear a
little (a successful saving throw vs. poison every round results in only 1d1O points of damage; failure indicates immediate suffocation).
So I decided to create a smoke base that had some slightly visible regions of cracked lava, and then dropped in some pathways that would be considered "cooler regions when compared to the brimstone". Naturally moving through (or even visiting) this plane is not advisable to the air breathing player, but sometimes you open the wrong door or a Smoke Mephit offers to take you on a guided tour of his home - in either case, bad tidings await!
First is the SmokeDemo 9 tile set: