Alien invaders behave intelligently before acting really, really stupidly in “The 5th Wave,” a tween-oriented sci-fi adventure that synthesizes “They Live,” “The Hunger Games,” and countless other visitors-from-another-world sagas. Based on the first of Rick Yancey’s series of novels, director J Blakeson’s film opens with young Cassie (Chloë Grace Moretz) running through the forest with a machine gun, finding a convenience store, and killing a suspicious man she suspected was hiding a weapon inside his coat. This marks Cassie as a do-what-you-gotta-do brand of heroine, and sets the stage for her ensuing ordeal combatting a race of extraterrestrials known as “The Others” who — for reasons that are never properly revealed — are bent on taking over Earth.
Flashing back to the day before The Others’ arrival, “The 5th Wave” details Cassie’s calm-before-the-storm Ohio high school life, an existence full of partying with her BFF, flirting with football player Ben (Nick Robinson), and spending time with her dad (Ron Livingston), mom (Maggie Siff), and younger brother Sammy (Zackary Arthur). Everything changes when an enormous UFO appears in the sky, and immediately sends out an electromagnetic pulse that disables the planet’s electricity and mechanical devices — an attack known as the “first wave.” Subsequent “waves” result in massive earthquakes and an outbreak of deadly avian flu, culminating with the now-openly-hostile aliens coming down from their perpetually airborne ship to inhabit human hosts, the better to infiltrate and exterminate with ease.
Having relocated to a forest refugee camp, Cassie is forced to go on the run when the army, led by Colonel Vosch (Liev Schreiber), transports all children to a nearby air force base, and exterminates their parents. Left behind trying to retrieve Sammy’s teddy bear — which, absurdly, she winds up carrying around for the remainder of the film — Cassie finds herself alone and in trouble. Her situation becomes even more complicated when she’s shot and, upon waking in a strange bed, discovers that she’s the patient of mysterious hunk Evan (Alex Roe). Meanwhile, at the base, Ben, Sammy and a group of largely anonymous comrades are given silly nicknames (“Zombie,” “Ringer,” “Dumbo”) and are trained by the blatantly evil Vosch and his nefarious right-hand woman Sergeant Reznik (Maria Bello) to become soldiers tasked with exterminating the warlike E.T.s, whom they can identify by using helmets equipped with X-ray visors that reveal if their adversaries have parasitic alien organisms clinging to their brains.
Early sequences of Cassie, her father, and her brother trying to acclimate to this new post-apocalyptic world order are adequately ominousness, even if they indulge in the sort of grim survivalist anxiety and foreboding that, years after the premiere of “The Walking Dead,” has now become clichéd. It’s not until later, when Cassie and Evan set out in search of the base where Sammy is being held, that “The 5th Wave” loses its footing, resorting to by-the-numbers teen romance in which Cassie gets hot and bothered surreptitiously watching Evan bathe in a lake, succumbs to his ultra-manly charms, and then rebuffs him — out of anger, and confusion — when he reveals his true, extraordinary nature. If you think their fraught-with-apprehension affair is the set-up for an eventual love triangle involving Ben, with whom Cassie shortly thereafter reconnects, well, you’re apparently familiar with “Twilight,” “The Hunger Games,” and the rest of their YA-dystopian ilk.
Moretz strikes a convincing empowered-badass pose but as no amount of charismatic fearsomeness can energize the illogical latter portions of “The 5th Wave,” which are driven by revelations about the aliens that, to put it bluntly, make no sense. Having displayed tactical shrewdness with regards to their human-extinction plans, the visitors proceed to employ a “fifth wave” strategy of almost mind-blowing idiocy — one that seems concocted not by advanced life forms, but by storytellers desperate to mold their tale into a rote don’t-trust-grown-ups formula. As child soldiers take to the battlefield, and heroes run around cavernous military base corridors, the film comes across as directionless, as if it were searching for a path toward something novel. Unfortunately, the conclusion upon which it arrives is merely a trilogy-teasing cliffhanger whose tediousness is compounded by the fact that what it portends — a futuristic variation of “Red Dawn” — is merely more of the rebellious-kids-vs.-adults same. [C-]