Diary takes the form of a "coma diary" kept by one Misty Tracy Wilmot as her husband lies senseless in hospital after a suicide attempt. Once she was an art student dreaming of creativity and freedom; now, after marrying Peter at art school and being brought back to once quaint, now tourist-overrun Waytansea Island, she's been reduced to the condition of a resort hotel maid. Peter, it turns out, has been hiding rooms in houses he's refurbished and scrawling vile messages all over the walls - an old habit of builders but gone nuts on his part. Angry homeowners are suing left and right, and Misty's dreams of artistic greatness are in ashes. But then, as if possessed by the spirit of Maura Kinkaid, a fabled Waytansea artist of the nineteenth century, Misty begins painting again, compulsively.