Perched on a tee of shaded ice, a boulder temporarily rests on Mutnovsky volcano's melting, debris-encrusted glacier. Explorer Franck Tessier scaled the red rock for a better view of one of the mountain's craters as it steamed toxic fumes into the sky (background). With author Jeremy Schmidt and photographer Carsten Peter, Tessier spent a month probing both the fire and ice of Russia's geothermal hot spot, Kamchatka Peninsula.

When the German naturalist Georg Steller came to Russia's Kamchatka Peninsula in 1740, he got a crash course in geology from the native Itelmen people. Having lived for untold generations in this land of smoke and ferment, the Itelmen knew exactly how volcanoes work.

Eruptions were caused by gomuls, they told Steller—ghosts of the Earth who lurked in volcanoes' cavernous craters. When hungry, they would leave their volcano and hunt the ocean for whales, grasping them with enormous, spear-shaped fingers and hauling them home to eat. Over huge bonfires the gomuls roasted mountains of whale flesh, sending clouds of smoke and vapor billowing up to the heavens. Rivers of boiling whale fat streamed down the slopes. The Earth shook, and whale bones flew through the air. Only when the gomuls were satisfied did the volcano fall back into steamy silence.

Steller, who later left Kamchatka to join Vitus Bering's second expedition to the North Pacific, asked how the Itelmen knew all this. They had found whale bones on the mountain slopes, they said. A few brave souls had even stolen to the rim of the crater, peered in, and seen the monsters' lair.