I agree. I was irritated all the way through at how everything kowtowed to the standard horror tropes, and then it took that turn which binned everything which had had me going "Oh, come on - they wouldn't do that!" Loved it. And even Emily Browning didn't look quite as alien as usual.I watched a really awesome movie a few days ago. The writer was great, because the ending was a surprise in every way. It's a horror story though and it ends on a sad note. I like movies that keep me guessing and sometimes prove my guesses wrong. This one proved EVERY guess incorrect.
It was called 'The Uninvited.'