So the duke was at war for many years by the orders of king, and a lady of lower noble house used his absence to temporarily hide in his mansion while he was gone. She told the servents that she was the Duke's lover/Duchess and got the treatment for the same. All the workers were totally trusting of this make believe mistress of the mansion. But then suddenly one day the master of mansion came back from war before she had the chance to escape. If I remember correctly, the duke when met the fake lady he asked her to keep managing the mansion instead of killing her. I read this one a while ago, and I don't remember the title. If someone can help me figure it out, it'd be helpful and appreciated.