6:45 AM on an ordinary Tuesday in Salt Lake City, Utah, a father and son lugged a heavy jewelry case into the lobby of a high-rise building. They ran a jewelry store together on the third floor, and had come in early to set up their new display. They heard the lobby door open behind them and turned to see a man holding a cardboard box. The man said he was making a delivery and asked where the elevator was. The father and his son were heading that way, too — so, all three got on the elevator together. As they stood, the father looked at the box the man was carrying. There was a name written on the top in black marker, but no return address, which seemed odd. And the man didn’t really look like a delivery driver, either. He was wearing a green letterman jacket, like a high school athlete would wear. But the father kept his thoughts to himself. When the elevator doors opened to the third floor, he and his son carried their jewelry case out and went on with their day. Later that morning, a firefighter pounded on the jewelry shop door and said that the building was being evacuated. The father and son rushed outside, where they saw fire trucks, police cars, and a crowd of other people who worked inside the building.