Every year in the highlands of Guatemala, the town of Sumpango celebrates Day of the Dead by flying kites. The kites are massive, the largest measuring 45 feet in diameter. Smaller kites, close 20 feet in height, are flown in a death-defying race down the side of a mountain. From a distance, the kites appear luminous and blissful, but the radiant colors of the kites mask an ominous subtext. On closer inspection, the images on the sails depict people in agony and torment: mutilated bodies, mass burials, kidnappings, and rivers of blood. In graphic illustration, the kites allude to the dark...