As a small family of foxes ran frantically from the pack of snarling wolves, they came upon a cave, shaded by a tree with strange, pink blossoms. They followed the winding corridors until a faint light came into view, shining from behind a layer of dense vines. No longer able to hear the wolves behind them, the foxes entered and looked around this unfamiliar scene, at the vines and flowers, subterranean ponds filled with strange creatures, and finally their eyes locked onto berries. These were unlike the berries they had gorged themselves on in the land above, shining a golden light and hanging from the ceiling upon lengths of vine. Reaching these berries required them to leap through the air, something they had perfected long ago. With each berry, a glow began to emanate from their bodies; for these first foxes, the glow lasted only a few hours, but the generations that followed developed a permanent glow, an adaptation which gave them greater visibility in the labyrinthine caves, which had become home. If wolves found their way into the caves, however, this glow could quickly become a detriment...