The welcome trend for horror movies to actually be creepy rather than merely yelling Boo! in your face or flinging a bunch of CGI severed heads into the camera continues with this home invasion horror thriller with a SF twist. In a sense it's taking those genuinely pantstaining moments from Insidious in which The Big Scary Monster Is Suddenly Standing In The Room Right Next To You!!!! and throwing aliens into the mix, resulting in the most enjoyable extra-terrestrial horror since the early years of The X-Files (before it got incomprehensibly silly).
As with Insidious, Dark Skies concerns an ordinary family with ordinary problems beset by an increasingly bizarre set of events: mysterious break-ins, blackouts, memory loss, bird strikes, marks on the skin, and ultimately the inexplicable physical presence of Something In The House targeting one of the children. And for the first act it feels like a traditional haunted house movie in that tradition. But while Dad Daniel (Josh Hamilton) tries to rationalise it (he's got more important concerns, including getting another architect job after being laid off), mother Lacy (Keri Russell) looks into all the symptoms and comes up with the craziest answer: aliens. Enter JK Simmons as the eccentric expert, who knows all about it, but can't guarantee they can keep the aliens from abducting the kid....
It kind of gives away its intergalactic twist in the opening caption by Arthur C Clarke: "Either we are alone in the Universe, or we are not. Both are equally terrifying", so you know it's about aliens as soon as the film starts. That's perhaps not as scary as the demons from Insidious or the evil whatever from Sinister, as the aliens are envisioned as the spindly "Greys" we're already familiar with, though there's still a delicious look-away frisson when Oh God They're In The House And Standing Behind You!!!! There's a nice plot twist concerning what the aliens want and whether they can be stopped which is nicely signalled earlier in the film, if you're paying attention.
Dark Skies is the best of Scott Stewart's films so far: far better than either Legion or Priest (and I kind of enjoyed Priest, for all its silliness). With a few immaculately timed jump moments and the alien creatures generally used very sparingly, it's pleasantly unnerving in places and certainly worth a look. Old-fashioned hokum it may be, but enjoyably creepy and perfectly well done.