SOMEBODY yelled and I arced the food bag back.

Twight was on his feet. We ground onward, two dark spots in a sky-size expanse of ice. Start and stop. Start and stop. Finally it was senseless to continue. We veered off to an abandoned, three-sided snow wall, dug out the drifts, and set up our tent. We were at 10,000 feet, already a day behind, but still intent on a quick ascent of McKinley—a few days acclimatizing on the West Buttress, perhaps a few days sitting out storms, then a three-day push up the Cassin.

In the morning we decided to make a cache to cut weight.

"This is way too much food," said Twight.

"Probably."

"No. This is fucking stupid!"

We had bought the food together. Two hours caroming down the aisles in a Colorado Safeway, pitching whatevereither of us wanted into the shopping cart. It was fun. We'd never climbed or hiked or even drunk a beer together before that. When the cart was full we figured we had enough. We split the food in the parking lot and parted. I was pleased to see how nonchalant he was about it all. It boded well, I thought. A week later we met in Anchorage at midnight, drove to Talkeetna in the wee hours, and were slowly skiing up the glacier later that same day.

The food bags were labeled "brkft," "lnch," and "dnnr." Twight muttered, dumped all the bags out in the snow, and started sorting the food one package at a time. Two hours later, we still had several heavy bags of food left to take up the mountain—which only made sense given it was just day three of a two-week expedition.

"It's still too much," groaned Twight.

"Fair enough." I grabbed one of the larger bags at random and threw it on the cache pile.

"What are you doing?" Twight was incredulous.

"Cutting weight."

In the end the bag went with us and our sleds remained too heavy and Twight started in again ten minutes up the trail. I stopped and told him I was ready to cut all the food. Cut the sleds, cut the packs, cut the rope.

"Take a water bottle, a candy bar, go for the summit from here." I was serious. I'd done it before on a dozen mountains. Twight thought I was mad.

Climbing the Cassin had been my idea. I'd asked Mark Twight to be my partner because he was a bold alpinist known for climbing fast and light, an ascetic philosophy I live by. But alpinism and mountaineering are not synonymous. Mountaineering—even if it's only a means to set up for a fast alpine ascent—often entails slogging under heavy loads for numerous days. Twight, as he later told me, abhorred slogging.

I, on the other hand, abhorred whining. Hence, though we may have been matched in philosophy, in temperament we grated on one another like fingernails on a chalkboard.

In many ways a climbing partnership is no different from any other intimate relationship. You sleep side-by-side, eat from the same pot, piss in the same spot, live cheek-by-jowl day in, day out. It's not enough that your heads be together, your hearts must be as well. Even in the mountains, the fabled redoubt where one wrong step can spell the difference between life and death, technique means less than companionship. And companionship is a matter of chemistry. Mysterious and invisible. And we didn't have it.

"So what do you say?" I shouted.

Twight said he did not intend to go any faster or lighter than he was going.