“Who can give me the derivative of X?” a high-school teacher asks early in the YA-apocalypse mashup The 5th Wave. As soon as she asks that, the lights blink off, everybody's cellphones die and jets tumble from the sky. We never hear a student respond, but here's my Official Fan Theory about this twisting, familiar story: The movie that follows is an answer to that question, the filmmakers' effort to offer the definitive derivative of X, a variable that in this case is forever in flux. Sometimes, it's The Hunger Games or Ender's Game, of course — can't have a dystopia without teens in military jumpsuits! And sometimes it's the blockbusters of yore: The city-sized motherships from Close Encounters and Independence Day send the tidal waves of many disaster movies to destroy our world's population centers.
Then there's some disease-and-refugee boilerplate before the Invaders From Mars business begins. The tweak: This time, it's the humans who have a mark on the backs of their necks. And then comes the paranoid X-Files stuff where the military and the aliens maybe might be working together — but rest easy, humanity, because the truth is out there, and a squad of sassy/conflicted teen warriors will stumble upon it about 65 minutes into the picture, with just enough time to spare for an improbable action climax and the setup for a sequel.
Oh, and there's some They Live, too, mixed with a pee-wee Call of Duty.
The storytelling is less about character than it is about waiting for the other shoe to drop, and there's always another — the movie is like a Payless sliding over a cliff. There are three waves of alien invasion to get through in the prologue, and then the nature of the fourth and fifth waves are minor surprises as the protagonist, Cassie (the always commanding Chloë Grace Moretz), hero's-journeys across an alien-ravaged Ohio in search of her tiny brother, who has been impressed into military service to fight “the Others.” Director J Blakeson and crew quickly, strikingly establish the end-of-the-world stakes, and there's grim gravity to scenes of Moretz scrambling to escape floodwater or steeling herself to shoot a potentially dangerous stranger. But the teens talk more as the movie goes, and I'm afraid that, outside Moretz, this cast is better at being posed against Armageddon than convincingly discussing it.
Moretz is a trooper, though, shooting, suffering and getting dewy eyed when she spies mystery hunk Evan (Alex Roe) doing the erotic bathe-in-a-pond routine. The romantic material is thinly written, but it's hustled through quickly — there's always another twist to get to. In that one key way the film is more engaging and effective than you might expect from a YA adaption (based on a novel by Rick Yancey) dumped into theaters in January: For a good hour or so, those who haven't read the books will be dodging shoes and trying to work out just what, after all the surprises, the premise will actually be. Turns out: It's familiar and underwhelming.
Also, since this is a Sony movie, we're treated to a shot of a character handling Sony-branded electronic equipment that in real life never has a Sony logo on it. In this case it's a cellphone that doesn't turn on because the aliens have wiped out all electronics with some kind of pulse. As product placement, that's pretty dumb: Here's a Sony product that doesn't exist but, if it did, would be inoperable in the event of the apocalypse.