What was the one book you read that was brilliant the whole way through, only to be let down by the ending?

[Connor]

Incidents Around the House was the one for me. I absolutely loved it until the last chapter.

[PJ]

Mona Lisa Overdrive. I really enjoyed it, and the conclusion for some of the characters is satisfying, but the end to the trilogy-spanning arc feels really stupid, like Gibson couldn't figure out how to tie everything up, so he pulls a multi-layered deus ex machina that would make Doctor Who blush. I suppose it's made worse by being the conclusion to an, up until then, outstanding trilogy.

On the flip side, The Man in the High Castle. The majority of the book is really trudging, but the ending is fantastically mind-blowing. I feel it would have worked better as a short story or novella, as (in my very humble opinion) Dick dwells for much too long on a counterfeiting subplot, which, although important to the final twist, could have made the needed point with a fraction of the pages devoted to it.

Oh, and one last dishonourable mention is of an old ghost story I read from a massive tome of classic horror short stories, many of which are fantastic. This one, however, drags on for ages before the nonsense twist that the protagonist was moving stuff around in his sleep. I really felt like I'd been trolled with that one.

[Lenore]

We Used to Live Here.
I hate ambiguous endings, though in rare occasions I think they can be good. Not this one though, it felt like the author kept adding things to a point he couldn't pull it together and decided like "okay, ambiguous ending it is". If I knew it'd end like that (I don't like reading too many comments before startinf a book), I probably wouldn't have read it. It was thrilling and intruiging but as I said, when nothing is explained in the end, it just feels like a waste of time