Hoping ""to resolve the unresolvable questions of my life,"" McCairen became the first woman since the 1950s to make a solo raft trip down the Grand Canyon, coursing the Colorado River from northern Arizona to Lake Mead in 25 days. Despite her extensive experience (she'd been rafting for 20 years and had traversed the Grand Canyon six previous times), many thought her solo trip foolhardy and were surprised the National Park Service issued her a permit. It was ""an impetuous decision,"" she writes, ""born of sorrow and despair,"" though she exhibits little heaviness of heart during the trip. Her reveries on loneliness and solitude come off as book-learned rather than life-learned. McCairen does, however, write very well about the river, the canyon's lore, and her trip aboard Sunshine Lady, her 15-foot raft. ""Floating the river is the easy part,"" she notes. Nonetheless, the journey involves hard physical labor: setting up and breaking camp, packing and securing her load at every stop. She has a grand time shooting the rapids and her descriptions of traversing stretches such as the Jewels, the wild Granite Narrows with waves 20 feet high, and the killer Crystal Hole comprise the most gripping part of her narrative. At Upset Rapid, she bitterly wonders ""what the hell happened to"" her confidence, as she balks at crossing, ruefully hoping for other rafters to appear, then a little angry when they do. By the time she reaches Lava Falls--nearly 100 yards wide, with a ""slot no more than ten feet across""--she accepts her fear as wisdom based on experience and is thankful others are near, just in case. As an exercise in self-exploration, it isn't much; but, as a trip down a challenging river, it's quite good.