Tilda Fenn had hunted the black swan for eleven days, and on the eleventh her sister's cough turned wet. She heard it through the cabin wall while she cleaned mud from her boots. The swamp bred sickness the way it bred flies, and the flies always came first. Whole clouds of them lifted from the reeds each dusk, thick enough to darken a lantern, and every one of them carried the bird's rot. The village elders called this the mosquito convention and told the young ones to stay indoors. Tilda's mother had died in the last one, six years back. Tilda had promised, over the grave, that she would kill the thing at the center of it. The swan was no ordinary bird. It had risen from the swamp once before, and her grandmother had put it down with an iron bolt, and still it had come back. Tilda meant to finish what her grandmother started. But the swamp was forty miles across, and she had walked in circles for eleven days, and each morning the flies were louder. She went to the trapper's shack past the sedge line and traded her mother's silver ring for a caged marsh hen. The trapper warned her the bird would not last the night. Tilda carried the cage to the highest cypress she could climb and tied it to a branch above the water. Then she waited. Near moonrise the hen began to scream, and something moved through the reeds without sound. Tilda saw the long, stiff neck first, held so still it looked carved. The sooty feathers passed under her boots and stopped at the base of the tree. It killed the hen through the bars without hurrying. When it left, it left a trail of black down and a wake that did not close behind it. Tilda climbed down and followed the wake through the dark. It led her three miles east, past a dead stand of tupelo, to a bed of matted reeds where the water went still and warm. She marked the tree with three cuts of her knife and turned back before the swan returned. She had the roost. She also had the ring gone, one night burned, and a wet cough waiting at home that would not wait much longer.