I don't like the direction the film took, but I just tried to enjoy it for what it was.

I can't totally justify the grandmother sacrificing her own daughter, but the closest we get to an explanation was the conversation the two had about the daughter having more children. She said she was done, her mother counters mentioning hopes for a son, she says no. I guess this decision makes the daughter dispensable and her death shows how ruthless the grandmother, cult, and demon(s) are.

If 4 makes sense of things I'll be ok with it, if we get more added to the story with no explanations I'll probably be done with the series. In the first film we learned that the family hasn't had any boys since the 30s right? I'd be interested to see who in her family made the deal in the first place. Then again, I was kind of hoping 3 would be a "real" movie and they would be able to continue the series without keeping it strictly "found footage".

When Toby pulled Katie into the closet and Christi finally said something along the lines of "I'll do it, just let her go" I was wondering if that was her agreeing to sacrifice her firstborn son...?

-edit- Thinking about it, I think the attempt to explain that was her dressing as a bride at grandma's and saying Toby was the groom. So maybe she was agreeing to "marry" him in the bedroom scene and with that would come the promise of her son.

I believe another theory could be that the think that Kristi said she "would do" was to either sacrifice her first born or agree to help kill her parents... i really wish they would be more specific about that, but im thinking that with the way the story ended i think the agreement was to help kill her parents.

And to comment on what Despare said: I liked that the second film explained the deal that was made and that it was in exchange for fame and fortune, but the thing that i dont get is, WHERE THE HELL WAS THE FAME AND FORTUNE?

I mean was anyone fortunate in any of these films?
i surely dont think so.

if anybody it was Kristi's husbands daughter that was forutnate just for the fact that she got to keep her life and Toby didnt really mess with her all that much.

I thought it completly fell apart at the end but it still managed to scare the hell out of me in the cinema, especially that part with the sheet that was fantastic, really had me on edge, ha.