You come into possession of an old box. Inside are several glass vials filled with dirt, dust and tiny bits of gravel or cement. The vials are labeled with places and dates such as, "Port Chicago 7/17/44", "Halifax 7/6/17", and, "Guernica 7/17/36". A trip to the library confirms that all are dates of massive loss of life in explosions. A few days later, a package arrives with no return address.
Inside is an empty vial labeled with your hometown and next week’s date.