A mysterious package discovered behind a wall in an abandoned building recounts the strange tale of twin brothers reunited after years apart. A school teacher’s quiet life is suddenly upended when he discovers his brother Sebastian — who thinks he is God — has had himself committed to a mental institution in Bangor, Maine, close to where he himself has been living for years. He records his visits with his long-lost twin and the conversations that leave him increasingly baffled, inspired, and finally uncertain about the thin line between sanity and madness.