The Flaming Forest by James Oliver Curwood

Into the stream Carrigan plunged and found it only waist-deep in crossing. He saw where Black Roger had come out of the water and where his feet had plowed deep in the ash and char and smoldering debris ahead. This trail he followed. The air he breathed was hot and filled with stifling clouds of ash and char-dust and smoke. His feet struck red-hot embers under the ash, and he smelled burning leather. A forest of spruce and cedar skeletons still crackled and snapped and burst out into sudden tongues of flame about him, and the air he breathed grew hotter, and his face burned, and into his eyes came a smarting pain -- when ahead of him he saw Black Roger. He was no longer calling out the Broken Man's name, but was crashing through the smoking chaos like a great beast that had gone both blind and mad. Twice David turned aside where Black Roger had rushed through burning debris, and a third time, following where Audemard had gone, his feet felt the sudden stab of living coals. In another moment he would have shouted Black Roger's name, but even as the words were on his lips, mingled with a gasp of pain, the giant river-man stopped where the forest seemed suddenly to end in a ghostly, smoke-filled space, and when David came up behind him, he was standing at the black edge of a cliff which leaped off into a smoldering valley below.

Out of this narrow valley between two ridges, an hour ago choked with living spruce and cedar, rose up a swirling, terrifying heat. Down into this pit of death Black Roger stood looking, and David heard a strange moaning coming in his breath. His great, bare arms were black and scarred with heat; his hair was burned; his shirt was torn from his shoulders. When David spoke -- and Black Roger turned at the sound -- his eyes glared wildly out of a face that was like a black mask. And when he saw it was David who had spoken, his great body seemed to sag, and with an unintelligible cry he pointed down.