Unfriended

The main achievement of this gimmicky horror is that it manages to hit all of the essential scary movie beats as the story unfolds in real time on a computer screen. Essentially a combination of the found footage and teen slasher genres, the movie relies a bit too much on loud noises for its most frightening moments, but director Leval Gabriadze also builds a terrific sense of suspense as the plot escalates. And by presenting it on a normal laptop screen, the film both looks fresh and has an eerie timeliness.

That laptop belongs to Blaire (Shelley Hennig), a teen who's having a lusty chat on Skype with her boyfriend Mitch (Moses Storm) when they're joined by their lively friends Adam, Jess and Ken (Will Peltz, Renee Olstead and Jacob Wysocki), and later by Val (Courtney Halverson). But there's also a mysterious unknown caller online who begins to taunt them about the death of fellow student Laura (Heather Sossaman) exactly one year ago. Is Laura's ghost using social media to get even with the teens who used a viral YouTube clip to drive her to take her own life? Or is someone else hacking into their system, controlling their screens and playing a game that threatens to kill them off one by one?

All of this plays out on Blaire's computer screen as she clicks from window to window using iMessage, Google, Instagram and Facebook to fill in the story with video, news stories and images, plus a panicky visit to Chat Roulette to get some help (as if!). The screen flicks around, showing conversations within chats as Blaire's mouse-control gets increasing shaky. So even if the plot itself is essentially a rehash of I Know What You Did Last Summer and Paranormal Activity, it generates plenty of overwrought emotion and scary jolts along the way.

It also allows the bright young cast to deliver extremely realistic performances that we watch in video chat windows. They may tend to scream and act utterly irrational from time to time, but no teen horror movie would be complete without that. And as we see more and more of Laura's humiliation at their hands, it's not easy to hope that any of them will survive. So the fun comes in guessing who will be next and how they'll get it, which is essentially how these franchises survive from film to film. So all it'll take is the next cool app or website to spark a sequel.

Unfriended Trailer