The novel takes place in Three Rivers, Connecticut. Dominick Birdsey's identical twin, Thomas, suffers from paranoid schizophrenia. With medication, he can function properly and work at a coffee stand, but occasionally he has severe episodes of his illness. Thinking he is making a sacrificial protest that will stop the war in the Middle East, Thomas cuts off his own hand in a public library. Dominick sees him through the ensuing decision not to attempt to reattach the hand, and makes efforts on his behalf to free him from what he knows to be an inadequate and depressing hospital for the dangerous mentally ill.

In the process, Dominick reviews his own difficult life as Thomas's normal brother, his marriage to his ex-wife, which ended after their only child died of SIDS, and his ongoing hostility toward his stepfather. Dominick also displays classic symptoms of PTSD, as a result of stressors in his adult life. First in Thomas's interests, and then for his own sake, he sees a therapist, Dr. Rubina Patel, an Indian psychologist, employed by the hospital. She helps Dominick come to understand Thomas's illness better and the family's accommodations or reactions to it.