Most of the cavity’s walls are hidden behind vegetation: fragile, cascading veils of moss growing from the rock, and vines depending from the branches of the trees hundreds of feet above them and dangling halfway down into the gorge, where they have become entangled with protruding tree roots and formed a natural trellis for a finer network of creepers that is itself the warp and woof of a matted carpet of moss saturated with flowing ground water. The gorge is alive with butterflies burning with colors of radioactive purity, and down closer to the rustling water are damselflies, mostly black with aqua bodies that flash in the sun—their wings revealing glimpses of salmon and coral-red on the underside as they orbit around each other. But mostly the air is filled with this continual slow progress of things that didn’t survive, making their way down through the column of air and into the water, which flushes them away: dead leaves and the exoskeletons of insects, sucked dry and eviscerated in some silent combat hundreds of feet above their heads.