Filmmaker Sarah Vanagt shoots with a small camera as she wanders through Brussels, where she encounters Polish, Iranian, Brazilian, Belgian, and Moroccan construction laborers, busy at work. At her request, they write notes addressed to future generations, and then hide them—beneath paving stones, inside pipes, or behind walls. Sometimes it’s a wish or reflection; sometimes simply a greeting from the present. One reads: “When you find this, I hope the... see more