Probably an. . .interesting novel. And I mean that in a good way, so don't worry. It's a Gothic novel (of course) written by Eliza Parsons. It's also one of those "horrid" novels mentioned in Jane Austen's Northanger Abbey.
Horrid? It must be good! 8D
It has the gloomy castle, a blameless woman in trouble, secrets, and good and evil. I have to admit, I was shocked at the climax. (No worries, I won't spoil it for you.) Let's just say that the uncle was insane. He practically hid the heroine away and neglected to tell her about the past until close to the end.
I had my suspicions about him...