The air was thick and static, the snow muffling all sound. I remained motionless, listening to my rapid breaths, my life reduced to the emerald-green boundaries within my goggles.

I was hesitant. I was afraid.

What if the snow was over my head? What if I couldn’t make it back up the hill?

Remembering the rope, I retraced my steps up the embankment to a cluster of boulders located at the base of the mountain, the smallest of which outweighed me by a solid ton. Removing the nylon rope from my backpack, I tied off one end around the nearest boulder and clipped the free end to the belt around my waist.

Feeling more confident, I backed down the hill, moving beyond my own tracks as I watched the GPS screen in my gloved hand.

I was chest-deep in snow when the target finder finally blinked green.

Working quickly, I freed the sensory device from its lead case, extended the support pole to its maximum length, and tomahawked the antenna into the snow drift so that only the octagonal sensor was showing.

I powered up the unit. Feeling a bit dizzy from the high oxygen content, I paused to rest while the sensory array triangulated.

I gazed overhead as the ice sheet rumbled like an approaching storm. Inching its way east toward Prydz Bay, the thirteen-thousand-foot-thick cap of packed snow was a living entity that affected the entire planet. For fifteen million years its weight had been held in check by an unseen magnetic source, and in the battle for supremacy, the resultant equilibrium had carved out a neutral zone where life had continued to flourish. Even now, the weight of the glacier was squeezing billions of gas particles of oxygen and nitrogen into the lake just so its trapped inhabitants could breathe.

Breathe.

Breathe, Zachary, breathe!

“Huh?” I raised my face out of the snow and gasped a breath.

Something had happened! Why couldn’t I see?

For a terrifying moment I thought I had gone blind. Then I realized I had lost my night-vision goggles. A horrible pain radiated from my chest, the tightness clenching me beneath both armpits.

I was spinning, dangling from the rope in complete darkness. Reaching out, I brushed a rock face. That’s when I realized what had happened—I had fallen into a crevasse.

How deep was the fissure?

Without my night-vision goggles, I couldn’t see my own two hands in front of my face.

Cold, scared, and disoriented, I did the only thing I could: I climbed.

Using the rope for support, I walked my way up the rock face using my spiked boots. The rope was eighty feet long, but half its length remained topside so it only took me a few minutes to reach the ledge.

Sensing a change in the air current, I pulled myself out of the crevasse and onto my heaving chest.