In the waning warmth of late summer, southeastern Wisconsin has become the stage for a quiet but accelerating crisis among its white-tailed deer. Epizootic hemorrhagic disease, carried on the wings of biting midges and nourished by standing water and heat, is moving through the region's herds with a speed that has turned ordinary backyards into places of unsettling discovery. The outbreak, which has also reached Virginia, reminds us that nature's systems are deeply entangled — that a virus, an insect, and a season can conspire to reshape a landscape before most people notice the pattern.