Well, it is a relief to hear that 2 other people did like it! I was beginning to feel like a bit of a freak.
aloha, I think you've got a bit fixated on the dead animals under houses stuff, I think that only happens twice rather briefly. And the snake episode is only a middle section of the book too.
Ok, we don't find out who killed Robin, but I don't think that was the point. The point to me was that it was about a young girl growing up in a house which was submerged in unspoken trauma. A trauma which happened when she was 1 year old to someone she never knew. What compelled me was the psychological effect of this event on her and her 'reality', the way she 'found' the murderer and chased him, the way she tried to speak out to people about her home / mother disintegrating before her eyes but there was no-one to hear. I don't think it's a book that one should approach with beginning-middle-end logic, I think it was psychoanalytical in that it was about what things mean and how they seem rather than being realistic. And to me that's my favourite. It's always a disappointment to have the mystery solved.
The other thing is how beautifully written it was, how atmospheric too. I'm not surprised it took 10 years and to me was far superior to Secret History.
By the way, I think the little friend was Hely and I think that's why the book ends on him. He was the only person to have faith in Harriet. Though even she couldn't see it.