WE ARE MOVING THROUGH A MYSTERY. Whiteness envelops us. We can't see where we are going. We can't see what lies to our left or right. Our only guide is ascent: We climb the fall line, crampon points and ice-ax picks skittering on verglas-glazed rock. There are just two of us on this expedition: taciturn Louisiana man Ross Lynn, 26, and yours truly. We're in a cirque with no name in the Daxue Shan Range, on the far eastern edge of the Tibetan plateau. It has been my personal dream to come here and climb. There are no rescue choppers or Sherpas, cells phones don't work, the nearest hospital is days away. Ross and I are on our own, inside the unknown.

We can't see them, but from the map we know there are four unclimbed 20,000-foot summits looming above us. We're hoping to climb just one, 20,059-foot Nyambo Konka.

A squall swoops in, hail rattling upon our helmets like gravel.

"Can't see a damn thing!" I shout.

But the higher we go on the mountain, the more sunshine begins to break through. Within an hour, the 4,000-foot visage of Nyambo is staring down on us. Blind to the terrain above, we've managed to climb right up beneath a deeply fractured, quarter-mile-long hanging glacier—something like wandering into a building that's about to be dynamited.

Ross and I make an abrupt right-angle turn, hustle across a vast, telltale fan of avalanche debris, and descend via a safer route on the north side of the cirque.

"Let's not do that again," I say on the way down.

"Scratch Plan A," Ross agrees.