Lenz, Georg Büchner’s visionary exploration of an 18th-century playwright’s descent into madness, has been called the inception of European modernist prose. Published posthumously in 1839, Lenz is a taut case study of three weeks in the life of a schizophrenic, perhaps the first third-person text ever to be written from the “inside” of insanity. Partially based on the memoir of an Alsatian pastor describing Lenz’s stay with him in 1778 (translated here in its entirety for the first time), Büchner’s text moves well beyond its source by the rapt and virtually autistic attention it brings to the details of the natural world, whose landscapes prefigure those of Cézanne or Van Gogh.