Diary takes the form of a coma diary' kept by one Wisty 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 Waytanses 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.
Angry homeowners are suing, 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. The canvases are taken away by her mother-in-law and her doctor, who seem to have a plan for Misty - and for all those annoying tourists...