The South Dakota winter gives a man time to think. One subzero morning, as Dan O’Brien approaches his fiftieth year, the autumnal equinox of his life, he takes stock. Feeling a waning sense of purpose, he decides to devote himself entirely, for the first time in his life, to his greatest loves—falconry, his bird dogs, and the prairie he calls home. That summer he obtains a remarkable falcon chick who immediately distinguishes herself by her ferocity. He names the bird Harley and trains her in the ways of falconry. Harley’s powers of flight are awe-inspiring, her hunting success astounding, and like a lover, she captivates him. O’Brien hunts with her obsessively, reveling in her prowess and beauty. What he learns from her and from what happens one wind-driven day lead him to see fully things he had only just begun to glimpse. In this lyrical evocation of the grasslands, Equinox is a story of a life lived close to the natural cycles of the earth and of a midlife revelation of the importance of staying connected to all things held dear.