The word revenant comes from the French revenir: a coming back, meaning a person who has returned from the dead. In Spanish, a person who reappears in this way is a ghost: fantasma, espectro, aparición. My ghosts do not seem interested in only one form of return: ninuno, anino—all my forebears, the line of ancestors starting with those I knew and could see until they became photos in an album, traced back to those who lived in some shadowy level of the cloud canopy but wondered what life on the ground might do to hands and faces and mitochondria. Multo, related to muerto: disembodied souls who float around in basements or attics, send their music through the plumbing, their morse code through radiators and wind chimes. So many more felled by bullets or bayonet thrusts in the last world war: their bodies rolled in reeds, their decomposing fragrance an unmistakable note in the wind. There are not enough words for every kind of haunting, especially the ones that pass through us or sit without moving in the middle of our lives.