They started from Kathmandu, Nepal, in September 1973: Peter Matthiessen, writer/naturalist and Zen Buddhist, on a pilgrimage to the Lama of Shey, and George Schaller, field biologist, in search of bharal, Himalayan blue sheep, in rut. ""In one day's walk we are a century away,"" crossing a landscape suffused with transparent silver light, and before long thoughts of sighting the rare snow leopard (bharal-he, or bharal killer) or the yeti (abominable snowman) are contemplated. Matthiessen has his tumpline fastened securely around this two-month, 250 mile trek with steadfast Sherpas, grumbling porters, and the occasional trail face. His numinous journal is a study in contrasts: Matthiessen himself, mood-sensitive and hungry for myth vs. Schaller the scientist, impatient and unassailable; these two eager sahibs vs. the restive carriers; Matthiessen the convert, fastidious in his Buddhism vs. Tutken the puzzling native, alleged thief and scoundrel, incomparable cook and companion. Matthiessen, who loves ""the common miracles,"" gathers the reader into his Buddhist consciousness, alternating explanations of prayer wheels or passed symbols with ruminations of life back home: years of drug experimentation, a wife's death to cancer, a young son left with friends. GS tends to insulate himself, coolly squeezing along a flimsy rock ledge with no handholds and calling it ""interesting."" But he can also exult over his onanistic sheep (""Oh, there's a penis-lick! A beauty!"") and, unobtrusively, write haiku on the trail. The preeminent field biologist gets his data and learns to anticipate leopard scat; Matthiessen finds his holy place, but contentment is more precarious. When the leopard ultimately eludes them, GS uncharacteristically turns philosophical: ""That was the haiku writer speaking,"" Matthiessen suggests. But he too transforms the letdown into a religious bonus, and the resolution rings true.