[Stephen]

From what little I have read about the plot/story it is being called a 'Blood relative' so it is related to the Cloverfield movie but its not being called a prequel or sequel.

So it is set somewhere in the same universe and timeline as the first film.

Goodman appears to be holding the girl prisoner and making sure she doesn't leave as well. So it sounds like that may take a dark turn.

Of course we could all be getting misdirected in a big way. That Shelter part may only take up the first hour or part of the film.

They also did a really good job of keeping the film hidden. Calling it something else entirely so as not to raise suspicion.