Alvarez (Off-Shore, 1986) slips down the literary slopes in this indifferent profile of his good buddy, mountain climber Mo Anthoine. Alvarez first met Anthoine in 1964; this book traces their friendship and Mo's mountaineering career--if "career" is the right word, for Anthoine holds climbing to be less a profession, or even a sport, than a pastime, a way of working up a sweat with friends. Anthoine seems an admirable but familiar chap: self-reliant, highly competent, committed to the best equipment and the best companions ("half my climbing life has always been in the pub"). Along with climbing, he excels as a movie hand (he worked on The Mission and other films as stuntman, technical adviser, cameraman, etc.) and as a designer of climbing equipment--his helmet is the best in the field, and he also developed top-notch gloves, tents, hammers, etc. Alvarez runs skillfully through all these facets of Anthoine's life, but little of it grips: the climber's life lacks the striking individuality and penetrating insight needed to make a compelling story (try last year's Living Dangerously by Ranulph Fiennes instead). Far more successful are Alvarez's tense accounts of two climbs--one, in which Alvarez participated, an ascent of a rock tower off the Orkney Islands; the other a disastrous assault on a 24,000-foot peak in Asia, ending with a perilous six-day descent through a raging blizzard, Sure to appeal to the climbing crew, but of little general interest--an object lesson, perhaps, in the pitfalls of writing about one's friends.