A narrow crevice in the rocky foothills of the mountains continually exudes foul, sulfurous gases from deep within the earth. About thirty paces inside the crevice, brimstone containing Ignem vis collects on the walls. The crevice is so narrow that even a small person can only negotiate it with difficulty, and the fumes and heat are so potent that an unprotected person will die within minutes. A simple Perdo Ignem spell can protect against the heat, but the gases are a different matter. Creo Auram will provide breathable air, but even so it would be difficult and dangerous to collect the vis. The fumes are also highly flammable, and those who attempt to penetrate the crevice using any kind of open flame as a light source will be in for an unpleasant surprise.