Just before dusk, the people of San Carlos disappeared into their houses and pulled the curtains shut, as if an air raid siren had gone off at a frequency I couldn’t hear. Then, as the sun sunk over the lake, the chayules came. Tiny green gnats, flying in thick clouds, crowding my eyes, my nose, my throat. I tried to cover my face, but they darted through my fingers and into my mouth and ears. The occasional car, sliding by like a ghost in the gloaming, would illuminate hundreds of thousands of insects in their headlights. Because the chayules are attracted to white light, all the light bulbs in San Carlos are dark red, giving the empty city a hellish scarlet glow.