November 2019. Bellflower, Illinois. A woman drives to Pender's Bridge after midnight because of a sound—a low, steady hum no one else seems to hear. There she finds Elias Copley, an old man who has been sleeping on the bridge for weeks, tracking its pitch like a pulse. He says the hum is the bridge singing its own collapse, and when the note changes, the steel will give. She listens. She believes him. She helps him block the road. But the truck comes anyway. And the hum does not stop when the bridge falls—it follows her home, down into the basement, into the foundation. A story about obsession, frequency, and the things we hear when everyone else looks away.