1)why was she hiding the mask thing under the house? 2)what was with the creepy look from the younger daughter in the end? 3)who gave the bloody stone mask to lena? 4)how did the guy kill ellie and why? 5)what was with the mple thing with ellie and her dad?
so lena from out that Inger killed her sister and posible her mother because lena ound the mask in lnger's bokkbag and inger knew she knew so she gave her an evil look to scare her. The guy lawson didn't kill her inger did because her and her sister has a mental problem in which they don't want any women to be with their dad so the do what the have to do so it will only be them and there dad.
I'll try to take your points one by one, as I figured them from my one viewing of the movie just yesterday morning:
1) Ellie hid the mask in her suitcase under the house because of the police investigation. It's not explained why she brought it up to her room later, but maybe it was because she figured the heat was cooling when suspicion in her mother's death began to point toward the neighbor.
2) Inger gave Lena that creepy look because Inger killed Ellie in retaliation for her mother's murder. Now Inger wanted her father's affections the way she suspects Ellie had them, and Lena was Inger's love rival, just as their mother was Ellie's love rival for their father's affections.
3) Lena found the bloody mask in Inger's backpack because Inger had put it there after she killed Ellie with it.
4) Lawson didn't kill Ellie. Inger did, out of jealousy for their father's attentions.
5) "I don't understand what "mple thing" means, but essentially, Ellie wanted to seduce her dad, so she got rid of her mom and started to work on his weakness. It's not really clear that they actually went through with the act, but they came close enough for the father to realize that Ellie could blackmail him by telling people that he slept in the same bed (and on the same sofa) with his daughters.
Hope that explains it more clearly! Still, this movie does leave a lot of strings dangling at the end! Intriguing!
To add to Debbie's comment, Ellie and her dad definitely had sex or did something that required them to be naked, thus leading Ellie to know about the "mole on [his] left ass cheek." She threatened to tell Lena if he didn't dump her; thus, in the next scene he ends their marriage.