"How did we keep track of what was going on? That was really hard," director Dennis Iladis says of his recently-release sci-fi thriller "+1." In it, teens at a wild house party discover that not only is time looping around them, but it's creating doubles. The film looks at three friends--David (Rhys Wakefield), Teddy (Logan Miller), and Allison (Colleen Dengel) as each finds their nights spiraling out of control as their doubles begin reliving the greatest and worst night of their lives.

We spoke with Illadis, who directed the 2009 remake of "Last House on the Left" as well as the harrowing drama "Hardcore" about teens in peril (in time) and what he would do if he met his own double.

"We took a narrative approach which was kind of a risk which was that the doubles are exactly the same people, except from 30 minutes earlier," Illadis explains. He says that the differences in between characters would be based on what those who'd already experienced those 45 minutes were going through, meeting their less experienced selves. "Very small things would make a huge difference," Illadis offers: an injury here, a bad reaction there, a first-timer who stops an embarrassing event from happening a second, third, or fourth time around, would create entirely new situations for their doubles. "The characters would evolve in those 45 minutes," he says, adding that the tiny details of what would happen to each of the cast members would prove very, very important.

On one hand, there's Rhys, a lovestruck teen who uses the night to get back with his girlfriend--and over time, the Rhys we meet at the beginning of the film isn't much like the one we know at the end. "Rhys really tries to manipulate the situation, tries to neutralize his double in a very manipulative way." On the other end of the spectrum, you have Allison, who Illadis says "can't connect" and therefore finds a kindred spirit with the only person at the party who can understand her: herself.

Dennis Illiadis on the set of "+1"

He describes David's pursuit of his ex Jill (Ashley Hinshaw) as an opportunity for "creative confusion" in writer Bill Gullo's screenplay (based on a story by Illiadis). "David is trying to spot the right Jill, because that Jill hasn't been exposed to his disastrous apology." Illiadis says that this allowed the creative team to have fun with mixed identities--which Jill is which talking to which David at the party? Which David was the one who'd cross the line?

When I ask if "+1" has a particularly pessimistic view of human nature, he counters that Allison's story is the most optimistic of the bunch. He describes her story as "extremely sweet." "She really embraces the phenomenon and her outcome is totally different. She comes out of this even fuller and more realized.

Illiadis says the project appealed to him because of three questions: what would happen if you got to meet yourself? What would happen if you were in the same space with yourself and both versions of you were going after the same thing? And finally, what if this space was a wild party where all of the emotions are raw and "there's no time to be intellectual and process things." It's for this reason that our cast of nerds, jocks, cool kids, stoners, losers, dancers, and others collide in such a violent fashion in the film's last act. "I love the idea of taking a very brainy sci-fi concept and grafting it onto a sort of raw, super-charged environment."

Watch: "+1" Red-Band 'Body Buffet' Clip

This space allows some of the partygoers to believe that their doubles are out to get them--a chance for "+1" to explore the concept of fear of the other when the other is ourselves, Illiadis says. "I think that has a lot of sort of sociological extensions," he says, adding that if he met himself at that age, he's not sure if he'd embrace or run away in fear from his own double. As an adult, he wonders how he'd react: "I have some intellectual fascination with this idea. Would you like what you see? Would you soon enter conflict rather than harmony?"

"+1" is out in theaters this week.