The air is thick with ice. You’d think that isn’t possible but it is. Every inhale sends sharp crystals of air shooting through my lungs. My chest tries to protest, clamping tightly around my heart. I ignore it. I have to. If I stop, if I give up even for a moment, it’s over. My life. I will be dead.

The thought spurs me on. Cold fingers grip my lungs, trying to drag them into the damp mud beneat...