Michael Caine once confessed that he’d taken an acting job, on occasion, for “the travel” – the chance to spend a few weeks or months in the Bahamas or Monaco. And every now and then one of his peers will let slip that he or she REALLY wanted to do this Z-grade vampire/ zombie/ slasher/ mercenary thriller because they’ve “never been” to Romania/ Namibia/ Belize or wherever.

Might that explain why Emile Hirsch, frittering away his residual “Into the Wild” goodwill, and Olivia Thirlby, growing out of her winsome teen pal-to-“Juno” years, signed on for “The Darkest Hour”? Hey, if you want to see Russia – safely, and on the payroll – there are worse ways to do it than playing Americans trapped in “The New Russia” at the moment the aliens invade.

“Darkest” plops a couple of just-ripped-off website developers (Hirsch and Max Minghella) and a couple of hot young tourists (Thirlby and Rachael Taylor) into Moscow’s vibrant nightlife and club scene, its burgeoning free-for-all capitalism (thus the “just ripped off”) and lets them survive the first hours of the conquest by mysterious nearly-invisible aliens. They wander the emptied city, roam the vast Westernized shopping districts (the women go shoe shopping, of course) and eventually touch base with the surviving Muscovites who are starting to figure out a way to survive and combat this new global menace.

The script, which has the handprints of writers of “The Alamo” (ouch) and the upcoming “Alien” prequel “Prometheus” (uh-oh), is generic in the extreme (“Run, RUN!” goes the dialogue). And the sole, limp gimmick here is that the aliens are electrical/ microwavable. Flickering light bulbs give away their presence, Farraday cages offer some protection from them.

Art director-turned-director Chris Gorak does nothing particularly interesting with any of this. The saddest moment may be when an anonymous dog is zapped, the funniest moment… well, there aren’t any funny moments.

“The Darkest Hour” might have lingered, a dark stain on many a resume, if it had any staying power. But it’ll be forgotten long before those Facebook photos that one and all must have posted during this working vacation romp. Word to the wise, kids – the frequent flier miles aren’t worth it.

Cast: Emile Hirsch, Olvia Thirlby, Max Minghella, Rachael TaylorDirected by Chris Gorak, screenplay by Jon Spaihts. A Summit Entertainment release.

Running time: 1:29

MPAA Rating: PG-13 for sci-fi action violence and some language