Verified answer

I don't really understand why or how Hunter was put up for adoption. The only thing that would make sense was that it was planned just so they could have access to a family with a virgin? Remember when they were joking that the character Alex could be used for sacrifice. I am still confused with that part.

Robbie was in my opinion some random other abducted possessed boy. (weirdoooo lol)

And those were not zombies! They were like members of a cult, or demon worshipping/following crazies. This is an extension of what was revealed in part 3.

There was something after the credits, go watch it on YouTube

The ending after the credits was a teaser for Paranormal Activity 5, which should be released next year. I am not sure if there will be any relationship between the rest of the series and the fifth part or if it is just a spinoff.

If it is a spinoff it might be in relation to the old housekeeper/nanny (Martine)

or...

Alex's boyfriend's relatives in Mexico...

remember in the movie when he is saying how bored he is going to be while visiting family in Mexico.

so I guess we will just have to wait and see....

oh and the translation from Spanish from the after credits scene was basically the man saying, "This is all witchcraft" which is why he starts leaving in a panic then the crazy woman says, "This is only the beginning."

In PA2 Katie got possessed by the 'devil' and took 'Hunter' and because you have to be a certain age to be possessed by the demon Katie didn't raise him, being the devil and all. So he was given up for adoption and his name was then changed to Wyatt. So he could live a 'normal' life until it was 'time' and in the movie Katie is saying "its aunt Katie.. it's time.. Hunter open the door, ill be here waiting when you're ready." now my thoughts on Robbie is that he was a normal kid and Katie found out its almost time and had Wyatt(Hunters) location she needed a way to get to him so she done something to Robbie's mother and put her in hospital so Katie could then play the part as "mom" to Robbie but of course if Robbie was himself he'd know Katie is not his mother. and she couldn't what so ever force Robbie to become friends and be close to Wyatt(Hunter) so 'Toby' -as heard of from PA3- jumped to Robbie and was then controlling him to get closer to their family until it was perfect for the demon to posses Hunter. I think Toby is a kid who was alive over 100 years ago due to the fact he had a 'special fork' and '100 year old teddy' hopefully there's PA5 to explain what happened but wasn't PA2 in 2006? and in PA4 it was 2009 so that would make Hunter only 4. which makes completely no sense to me.

Too many loopholes... We'd be here all night...