Hallowe'en is approaching, and in the absence of any more Saws, the current reliable once-a-year horror franchise is now Paranormal Activity. We've already seen a teaser for the fourth instalment, but since that one really didn't tell us much, here's the second Paranormal Activity 4 trailer, which goes into rather more detail.

The last clip just about mentioned the creepy kid across the street, but if you hadn't guessed, it turns out that it's Katie's kid, going by the name of Robbie (apparently Damien was taken). The question is, is Robbie actually Hunter?

Paranormals 2 and 3 were both prequels, but 4 finally gets into the what-happened-next territory of Katie and Hunter's life after their disappearance. Turns out they've been hiding out in suburbia, but when something happens that seemingly puts Katie in hospital, Robbie has to go and stay with the new neighbours. That's not going to end well.

The first film seemed to suggest that the paranormal entity was some sort of stalker poltergeist that was in love with Katie, but that's been lost and tweaked along the way. The prequels ended up with some business about witches, and we now appear to be dealing with the ghost's transference to Hunter. Is there a grand plan, or are the production team just winging it? It'll probably be a while before the series is finished and all becomes clear.

The directors of Paranormal Activity 4, as with 3, are Ariel Schulman and Henry Joost (Catfish), and we're liking their new found-footage twist of an ongoing Skype conversation (also exploited in the excellent V/H/S). Oren Peli, Jason Blum and co. are the producers as usual, and the film's out in the UK on October 17.