"Everest," writes British climber Bear Grylls, "is no place to prove yourself. The likelihood of reaching the summit is so slim that you're inevitably setting yourself up to be disappointed." But, Grylls continues, mountains are most definitely an arena where alpinists express their deepest drives, and he had more ambition than most. Badly injured in a parachuting accident in 1996, he resigned his army commission and cast about for a new career--a decision he succeeded in putting off by enlisting in a climbing expedition to the world's tallest mountain. Now, Grylls points out, the odds of a well-conditioned climber's making the summit of Everest are something like one in a hundred; for climbers under the age of 30, who lack the experience and conditioning that age brings, those odds slim down to 1 in 1,000. Twenty-three at the time, Grylls took his chances nonetheless, despite the "sinking feeling that I had just made a commitment that was going to drag me a little too far out of my comfort zone."He fulfilled his commitment, though surely not without discomfort, scared but determined, making his way up deadly obstacles such as the Lhotse Face Icewall and its deep crevasses. Other climbers were not so lucky, he writes in this you-are-there account of his time on the mountain, and death is a constant presence on these pages--which may deter readers who seek to follow in his footholds. For those content to travel up sheer rock and ice walls vicariously, though, Grylls's book is a spirited exercise in adventure writing and a promising debut. --Gregory McNamee