A cabin rises beside a pond in the Massachusetts woods, built for twenty-eight dollars and twelve cents by a man determined to reduce life to its essential facts. Henry David Thoreau lived at Walden Pond for two years beginning in 1845, and the book he published in 1854 compresses that experiment into a single cycle of seasons, from summer's heat through the deep silence of winter to spring's thaw. The prose is dense, aphoristic, and lit with sudden flashes of ecological attention that anticipate an entire tradition of nature writing. Thoreau is not gentle. He is rigorous, impatient with comfortable lives, and his demand that we examine our quiet desperation remains as unsettling as the morning he first heard the pond crack with cold.