Dust, invisible and light, surrounds us, floats in the air, settles on our clothes, is carried and spread by us—and usually goes unnoticed. It can come from a wide variety of sources: rock, soil, sand, the ashes of our ancestors, pollen, gold dust, sulfur, or mercury. We ourselves are made of dust and are directly connected to it. Therein lies a great power: the fleeting, elusive dust that is considered an intruder and feared because we do not know what it contains.