It's been a long while since I've posted here, so let me come back triumphantly by posting a new site!
The Caldera
Within the Plane of Ash lays a vast, dark lake. The lake’s waters, though darkened and chilled by the ash of the plane, are mysteriously pure and good to drink from. The water rests in the basin formed by a large, obsidian caldera. The caldera was once a roiling pocket of magma that burst and erupted like a volcano until the frigid, heat-sucking force of the Ash stole the pocket’s fire. It has since cooled enough to contain a large pool of placid water.
But where did the water come from, and how can the water maintain liquid state? Graybeards who know of the site have pondered this question for quite some time. They have deduced that the water can remain liquid because the obsidian that forms the caldera remains warm enough to keep the water from freezing. That still leaves the question of where the water comes from. A noted dao geologist, Emir Tal’Shid (TN male dao expert 6/wizard 2) has suggested two possible theories. First, the volcano had always been an underwater volcano, but that the heat-draining nature of the plane caused the steam from the heated water to condense immediately. His second theory is that the water was formed by condensation of escaping gases as the magma cooled and became the obsidian basin.
Strangely, the water is good to drink, though it is darkened from the ashen silt that has saturated it. The water even seems to have a beneficial effect on those stricken with illness or poison. The reason the water is potable remains dark.
Natives of the plane of Ash don’t much like the Caldera. A few ash mephits have hinted that the place is still moving, in danger of erupting again. While many Ash creatures feed hungrily on fire, they don’t like the magma, perhaps because of the violence with which the Caldera used to erupt.
But that also doesn’t mean they particularly like berks stealing the water. The water, maybe because it has ash in it, is something the natives are rather possessive about. Any leatherhead barmy enough to try and reach the Caldera is likely to find some angry mephits or ash quasi-elementals in the area just waiting to eat the warmth from their bones.
Ash Water: Mechanics
The nature of the ash water’s curative properties is rather unknown, but anyone who drinks ash water from the Caldera gains a +4 check on his next save to resist a disease or poison already in effect on him.
The trouble about this water is actually keeping it in drinkable form. As soon as a body pulls it from the lake of the Caldera, the water freezes solid and if you try to drink it off the plane of Ash, it just tastes like dirty water and provides no beneficial effects.
Others' Hypotheses
Rip has suggested that perhaps the water in the Caldera's lake is the essence of a water spirit of some kind. He believes this would explain the healing properties of the water.
I could also see it as a slip of mist near the edge of Mist and Positive enery. Given a point that's become sort of 'mixed' between the planes, where Magma broke through briefly and was quenched, Mist broke through and still keeping the warmth from the closeness of the Magma... absorbing the heat, condensing from the Ash, but because the mist was from close to the positive.... retaining the healing properties.
Of course - then you'd have to worry about why, in this particular spot, the planar boundries are failing and allowing things to mix. But that's a whole little adventure hook right there...
(Poke. Portal submission. Poke. )