The Journals of Sparrowhawk
You’re walking towards a great volcanic peak. Hot sulphurous clouds surround the top of the mountain. The closer the group gets to the peak, the hotter and darker it gets until the only light available is the red glow from molten lava slowly flowing down the mountain towards them. When only a few hundred feet from the summit the flesh on their limbs and faces start to bubble and burst. Great pain wracks their entire bodies.