Until the French government declassified documents concerning their ignominious defeat at Dien Bien Phu, Madam Daeng's past had been a well-kept secret. Now Dr Siri's wife is vulnerable and being stalked by a killer.

But when Dr Siri whisks her away for a romantic working weekend, they encounter an even greater threat. For Dr Siri falls under the spell of a beautiful witch they call the Used-To-Be Woman.