The driver turned off the engine of his rumbling Russian- army troop carrier at the edge of a deep canyon carved by a stream of glacial meltwater. Our little research group--which included Stanford graduate students Jamie and Meaghan, postdocs Jan and Jake from the Carnegie Institution of Washington, and our guide, Vladimir--clambered down from the truck for a welcome stretch after a jarring five-hour drive from Petropavlovsk. Then we shouldered our packs and began to climb, crunching over packed snow and ice between house-size boulders. When we stopped for breath and looked back downhill, we could see the ash and lava flows from past eruptions eroded into hills and valleys, with scattered patches of low shrubs in sheltered areas far below. The jagged volcanic landscape of Kamchatka defined the horizon. Above us loomed our goal: the blasted peak of Mount Mutnowski, a volcano that had erupted just a few years before.

Two hours later and 2,000 feet higher, we peered over the edge of the crater. It was hard to grasp the chaos beneath us. There was nothing alive in this landscape of black and gray rock except our team of six. A small glacier on the other side was melting into the crater, and distant roaring sounds emanated from deep inside as steam rose into the blue sky. Earth, air, fire, and water, I thought--the ancient elements, brought together here in far eastern Russia, stirred by heat energy left over from the beginning of our planet's history. Except for the glacier, this place seemed like a remnant from that time--a model of what Earth was like four billion years ago, before life began. We made our way down into the crater, at times wearing gas masks to protect our lungs against caustic gases.