Many writers of climbing fiction invent their own mountains. Not Nicholas O’Connell. Drawing upon his own ascent of Denali, he gives us a vivid--and appropriately chilling--picture of this coldest of North American peaks. “As the angle of the slope steepened, the air grew thin, the sky blue-black, and the full moon appeared as close and brilliant as a newly minted coin. It seemed like we were leaving the earth behind and climbing into outer space.” The descriptions are not always so poetic, but realistically gritty: “I found nothing attractive about the climbing. I simply bashed my way up it, pulling in gear, driving in pitons when I needed to, slogging my way up.”

O’Connell’s characters are not attempting merely Denali, but a new route, really a major variation, on its forbidding southern side. The specificity, as well as the rendering of landmarks on the approach, confers credibility on the narrative. Expedition details--logistics, tents, gear--are likewise convincing. So is his attention to food, still a significant challenge even in the best-planned of trips. O’Connell does have a familiar problem: How to employ technical terms for a general audience. Thus we are told what a 5:10 is, how jumars work etc. Once past this obstacle, O’Connell uses his climbing terms smoothly.

This Denali throws everything in its power against its challengers. There are crevasse falls, avalanches, rock fall, incipient pulmonary edema and the inevitable storm. The climbers endure personal conflicts, bad judgment, ambition and fear--all the pleasures of a serious expedition. With his characters, O’Connell is less successful than with their environment. The four climbers are largely generic, and their copious dialogue does not well differentiate them. The principal two are Wyn, single-minded in his ambition, and John, strong but conflicted about leaving his wife and child behind. John’s lack of depth is notably regrettable, as he is the narrator. He, and thus we, see relatively little of Lane and Al, the second rope. Once O’Connell has to let John overhear their conversation is a neighboring tent to let us know what they are really feeling. An omniscient point of view might have served the novel better.

Like many an expedition, this book starts slowly. It does, however, generate considerable excitement as the climb goes higher and dangerous decisions are made under stress. Here we have the real thing: exaltation, suffering and other consequences of trying something this hard with a group that never really becomes a team.