No pun intended - even with having seen so many movies, you can be and get surprised from time to time. Maybe you will be able to figure certain things out way before I did. The movie tells the story very nicely and it leaves it a bit up to you to ... see and believe what you want to. Although according to the director a lot of the things actually happened in the house they shot (his own family house for over 200 years).
Well haunted house or not, there are other issues and dangers lurking around. "Real" ones that is - and also quite female orientated! Kudos - I do not think that is a bad thing, quite the opposite! And while I talk about sticking together, that doesn't mean there is no friction and disagreement! Also do not confuse this with another french movie called Frontiers ... which was way more fast paced ... and had a lot more violence! This is more psychological to say the least ...