Amid the mayhem of the Civil War, Virginia plantation wife Iris Dunleavy is put on trial and convicted of madness. It is the only reasonable explanation the court can see for her willful behavior, so she is sent away to Sanibel Asylum to be restored to a good, compliant woman. Iris knows, though, that her husband is the true criminal; she is no lunatic, only guilty of disagreeing with him on notions of justice, cruelty, and property.
On this remote Florida island, cut off by swamps, seas and military blockades, Iris meets its wide-ranging collection of residents — some seem sane, some wrongly convinced they are crazy, some charmingly odd, and some dangerously unstable. Which of these is Ambrose Weller, the war-haunted Confederate soldier whose memories terrorize him into wild fits that can only be calmed by the color blue — but whose gentleness beckons to Iris?