Help Explain!!!!!! Spoilers in answers!!!!!

I liked Insidious, but that is just me. Most things I have seen lately have NOT been scary at all. Maybe there will be a scary scene, like there are some scary scenes in the movie END OF THE LINE and also that movie CREEP. Actually, End of the Line bothered me for awhile afterward. The concept was kind of creepy. It is low budget and some of it is hokey but some of it is really creepy. Insidious bothered me because of some of the scenes but also because I used to always read stuff on astral projection. Scary!

I had a lot of the same thoughts as you guys, but the end made me wonder more.

I may have misheard, but at the end I thought the doctor called Elizabeth 'Rebecca'... Granny's name. As confusing as everything was, that part made me wonder if the entire thing was just in her head and she was incredibly insane and delusional.

The wild, cruel animal is not behind the bars of a cage. He is in front of it.

I applaud you for your inventive theorizing but I think you are going too far outside of anything contained within the film to force some semblance of sense into something wholly nonsensical.

1) I can't say I recall any specifics of any superstitions that claim water as a doorway. Water is "the life giver" and generally takes on symbolism of cleansing. Outside of the Christian/Biblical realm, it has a near universal undertone of purity and fertility. In Taoist tradition, water is considered an aspect of wisdom. Ancient Greece saw it as transition and as a symbol of metamorphosis and philosophical recycling. In short: Transformation, Subconscious, Fertilization, Purification, Reflection, Intuition, Renewal, Blessing, Motion, Life.

I've emboldened the one most fitting were anyone going to go so far as to insist the presence of water meant anything... but sadly I don't feel it does so in this film.

2)The actual superstition with mirrors insists that any mirrors in a room where someone has recently died must be covered so that the dead person's soul does not get trapped behind the glass, not as doorways to another dimension. The dimensional thing is a relatively recent construct and has more to do with fiction than any established mythology.

3) In order to arrive at your conclusion about what was being passed, one would have to excise certain other portions of the film that basically construct what little narrative there is as a variation of the "it was all a dream" cliche. There are few things one can do to gut an entire narrative than having a cop-out ending where everything is revealed as "just a dream" because, at that point, nothing that happened in the film "mattered" or even happened.

Going back and examining or analyzing anything that occurred outside of the ending (and maybe the injected interrogation scenes) is futile because the ending tells us some 90% of what we have seen were events that never actually occurred except in the girls mind. The only way to circumvent this is to believe that the revealing ending is actually a farce and never really happened, which brings in a slew of narrative issues.

4) I'm confused at your point here as you are stating that Dad apparently never visited Grandma when the story only specifically mention the grandchildren never visiting, and "Billy, too!" is impossible because the Caretaker, who mind you is now seemingly the psychiatrist, was far too familiar with Billy.

Dad really objected to the kids staying there without supervision. He made no other real objection.

There is also the issue of the remarkable resemblance the end scene setting has to the estate, as in they are the same interior... which goes back to my thoughts on #3.

5) The box had the mirror with it, but not in it. The OP's question was specifically what was "in" the box. Papers. Given #3 and because of the ending, we don't even know if there was a box and, as #3, one would have to again ignore the last 2-5 min of the film. For all we know, the contents of the box, represented her admission papers to whatever institution they showed her to be in.

6) Here's where much confusion about the extremely disjointed narrative comes in full force: at the bookends. If one accepts the epilogue as true to the narrative, the prologue with the two individuals and the box makes no sense in the context of the story because we'd have to believe Elizabeth constructed a detached situation with which she is uninvolved. Accepting the prologue as true to the narrative, however, renders the epilogue unnecessary. One of them does not fit with the other.

7) Lisaplus1's question on Billy is answered within the dialogue through the papers our protagonist's found... that is if any of this portion of the story is real. Ultimately, it's incidental as the Billy subplot adds nothing and seemingly has no real relevance to any of the events throughout.

The only relevance Billy may have is as another patient at whatever institution we were to come away at the end as believing Elizabeth is in and that she made him into a relative within her fantasy. Even this is a stretch of the imagination as there was no reference to Billy in the epilogue to imply this or otherwise.

8) Lisaplus1 asks if Charles is real. Apparently he is, as we see a different Charles at the end in a different capacity than the Charles we'd been watching through the entire film. Again, to accept the servant Charles as real or a ghost belies the ending revelation.

9) You state: "...but then they take you from hospital & psychiatrist & merge over to the estate & Charles in the ending." I'm not sure I understand where you are going with this because when the supposed attorney is taken into the glass, the scene morphs into Elizabeth looking out that same window and the doctor version of Charles (not the servant version we've been seeing) talking to her about a new medication before leading her by the hand up the stairs to bed. At that point, the film cuts immediately to the end credits.

Either way, this epilogue points more toward the "estate" and the institution being the same place.

10) It would be a redundancy to explain how #10 falls into the whole issue of which set of events actually occurred.

The issue, from a narrative point of view, is in the chaotic way the film has been edited, the disjointed narrative, and making the estate and the glimpse we have of the institutional setting one and the same. The latter of these really confuses the follower because why, when relaying the story to detectives, would she bee seeing the institution as the estate before she were ever placed there... unless she were being held there during the time she was being interviewed and thus this setting became part of that fantasy. This, however, seemingly conflicts with the detective's dialogue about sending her to the institution.

In closing, the film seems to imply to us that some semblance of events occurred where the girl's siblings were killed and, if we are to accept the statements made by the detectives and parents in the interrogation scenes as truth along with the brief epilogue, she was responsible but unaware of her actions as her mind has constructed this entire dissociative fantasy around it. This is unfortunately lost within a slew of narrative contradictions to both directions the film takes.