Sometimes I can’t believe it was me. On my first trip to Pakistan, in 2004, my friend Josh Wharton and I had our eyes on an unclimbed route on Great Trango Tower. From base to summit it rose for 7,400 vertical feet of technical rock climbing. Between us we carried a 28-pound backpack, two ropes, a rack of gear and a preternatural belief that bordered on magical. We completed our climb in four and a half days — the final two without water. On our last night, anchored to the rock in our sleeping bags, we watched the sun set over serrated ridgelines and an ocean of snow-capped mountains. Beneath us, over a mile of air dropped to the glacier. I loved feeling so small.

In February 2010, at age 41, I was in Montana, climbing better than ever. I’d been road tripping from my cabin in Colorado, after having come out of a very rough patch: My fiancée had nearly died of a rare brain disease, and during the month that I lived by her hospital bed, one of my best friends was killed in a climbing accident. Now, with the help of loved ones and the single thing that has always brought me joy — climbing — I was regaining my life. Friends and I were making plans: local routes on rock and ice, Alaska in the spring, Pakistan in the summer.

I had gone out for a day of ice climbing. On our warm-up route, I led and a friend belayed. I secured the rope at the top, then paused, taking in my surroundings in a moment of gratitude after the hellish previous months. The rope felt tight, but I didn’t confirm it with my partner below. Stupidly, I leaned back — and fell. I dropped only 10 feet before the rope stretched taut and caught me. But as I fell, my extended leg hit a ledge and my crampon bit into the ice as my body continued downward.

The next thing I knew, my lower leg was flopping to the side. Six surgeries followed in 13 months. I worked hard at rehab, and as soon as I was able, I returned to some of my old alpine haunts — Chamonix, Pakistan, Alaska, Patagonia. But I found myself increasingly distracted by pain, more scared, less confident than before. Inside my ankle, the remaining cartilage was rapidly disintegrating. Soon the bones were grinding together. With each trip, I felt like I’d aged a decade. Trying to be optimistic, I figured that even if alpine climbing was over for me, I could find satisfaction on gym walls and roadside cliffs.

Doctors eventually fused my ankle, which removed the gnawing and grinding that had left me in a haze of pain. Like the aging boxer who can’t let go, I began to dream again. But it didn’t last long. As a child, I had fractured a vertebra playing backyard football. Over the decades, it had slowly degenerated. Now spinal nerve pain was ramping up, pulsing and insidious. On good days I could still climb, so I’d hobble to nearby crags. On bad days, thunderbolts rolled from my spine and down my legs, and I would curl into a ball, disengaged from the world. It seemed like forever since I had known the person whose heart sang in the mountains.