WHAT ARE THE ODDS? That one man's bare behind, hung off the Long Ledge bivouac near the top of Yosemite's El Capitan, could deposit all its foulness directly on our heads, with us 600 feet lower and dangling from our ropes? I mean, really, when you consider the powerful crosswinds, the ubiquitous updrafts, and the rather loose character of most big-wall bowel movements, it's got to be one in a million.

But that's exactly how it happened. My two climbing partners and I were 2,000 feet off the ground, three days into a five-day ascent of the Salathé Wall, widely considered the finest pure rock-climb on earth. Reuben Margolin, our mad and jovial visionary,

We heard a whistling sound, the terrifying evidence of an object hurtling down from above.

had just led a very hard pitch, and I stood a rope length below, with our Fish haul bag and our steely-eyed enviro-warrior, Jonathan Kaplan. Then we heard a whistling sound, the terrifying evidence of an object hurtling down from above. Instinct told us it had to be a rock, so we hugged the cliff and awaited the worst—and the worst certainly came, though it took the form of countless fecal asteroids splattering across our heads and shoulders.

Stunned, Jonathan and I stared at the wet brown pie on the bright-red nylon top of our haul bag. Our next bath was 48 hours away. We had no soap, water was in short supply, and that instant hand-sanitizer stuff hadn't even been invented. So we were screwed, and we suddenly started screaming like stuck pigs, cursing the careless bastards high above and then cursing them some more. After that we dug out a pocketknife to cut every soiled sleeve off our shirts and to snip big locks from each other's hair. With a few lukewarm drops of water we made a hopeless attempt to scrub the fresh human feces from our already filthy skin, and then we did the only thing we could do: We climbed onward, muttering bloody murder.

But the next evening, when we reached Long Ledge, we found something surprising: a plastic bag with an apologetic note (SORRY, DUDES, WE DIDN'T KNOW YOU WERE THERE) and a peace offering that included a box of Lemonhead candies, a can of chicken meat, and a joint. We had plenty of treats of our own, and I'd stopped smoking pot in the 11th grade, but I loved the gesture. Lame though it was, it conjured the guilt they must have felt, their sense of common cause with us, and the bond we still shared, simply for having been on that spectacular wall at the same time, together.