I am desperately trying to find a book I read about 30 yrs ago. Unfortunately I can't remember a great deal about it, but here goes. I think it was set in Cornwall and it was about a strange family - two of the names I recall are Veryan Treveryan and Lirryn Treveryan (don't think I've spelt them correctly) - it has a gothic feel to it with lots of dark family secrets and the children made a pact to never marry, but one of them breaks the deal and it leads to a tragic end. That's about all I remember, hope someone out there can help me, thanks.