Again, the cloud library description suggested there was some werewolf-ish-ness. I thought to use this for the werewolves bingo space.
No such luck. There was one little brief whiff, not enough to count.
Worst of all, it was a really stupid book. I could have counted it for Gothic, but I wouldn't insult my Bingo card with it.
Presented as Harriet Barton's diary, there's no sense of immediacy. It reads like a traditional past tense gothic.
The characters are stereotypes. Ada the fluffy blonde beauty, who proves stronger than she looks. Harriet is the ugly, dark, smart one. Julian is the "good" brother; Francis the "bad" one. Even Harriet's ruminations on the unfairness of English law that deprives Ada of her inheritance wasn't enough to make these characters interesting.
The ending was eye rollingly bizarre. First of all, did Harriet sit there in the tower room with her pot of ink and pen and write all that? Second, what happened to the dog she drugged? Did it just wake up and then go after their prey? And her whole emotional paralysis afterward, just lame.
I love Barbara Michaels, but this book was terrible. Fortunately, it was short and had a lot of white space.
EDITED TO ADD --
Copyright is 1967, so this was one of her earliest books and very clearly modeled on the paperback gothic romances of that era. However, I read quite a few of those and still have some, and this didn't even stand up in comparison.