Twilight of the Mississippi is a haunting look into the troubled environment and psyche of the American Heartland. It follows the journey of the Unseen Ghost Brigade, a theater troupe that built a raft and traveled down the Mississippi River in 2010. The story explores the marginalized communities of America, a dense patchwork of endangered worlds, with the river cutting through the middle of them all. Winona LaDuke, the National Park Service, industrial farmers, fishermen, spiritualists, anarchists, river rats, a black shaman, and the Army Corps of Engineers: this documentary presents their stories, secrets, and the dark comedy of America's River.