+1 (also known as Plus One and Shadow Walkers) is a 2013 American science fiction horror film[1] directed by Dennis Iliadis and starring Rhys Wakefield, Logan Miller, Ashley Hinshaw, and Natalie Hall.

While on the phone with his girlfriend Jill, who has moved away to attend college, David prompts her to explicitly wish that he were there to see her compete in a fencing tournament, only to surprise her with an unplanned visit.

After the competition, David approaches Jill's similarly attired opponent from behind and flirts with her, thinking she is his girlfriend.

Later, David meets with his friend Teddy, a sex-obsessed student who tells him that Jill will attend a house party later.

The wild revelers do not notice brief, anomalous phenomena that occur during the blackout, such as a mirror image out of sync, but a drug dealer's girlfriend outside the party becomes spooked.

As the raucous party proceeds, David searches the house for Jill, and Teddy attempts to charm Melanie.

Meanwhile, David spies on Jill as she flirts with a friend, and Allison, an outsider, unsuccessfully attempts to fit in.

David confirms that the house has filled with duplicates of the partygoers, who repeat the actions their originals took ten minutes ago.

Additionally, Chrissy Chambers and Ronke Shonibare portray strippers Kitty and Katty, respectively.

[7] In an interview, Dennis Iliadis said that he asked himself three questions: I don't think the key word is "horror".

I think it belongs in the science fiction thriller mold, but it's a genre film that combines a few things.

[13] Rotten Tomatoes reports that 82% of 11 surveyed critics gave the film a positive review; the average rating was 6.6/10.

[15] Jeannette Catsoulis of The New York Times made it a NYT Critics' Pick and called it "a fleet and frenzied sci-fi tale with more on its mind than alien gate-crashers.

"[16] Chuck Bowen of Slant Magazine gave the film three out of four stars, commenting that Iliadis did a good job of showing the "existential despair" of narcissism and detachment.

[17] Scott Weinberg of Fearnet gave a more mixed review, saying that the film was a "decent, uneven, well-made spin on a very standard horror story".

[18] In a mixed review, Geoff Berkshire of Variety called it a "trippy oddity" with "a tantalizing visual puzzle that demands full attention, even as the flavorless characters and largely so-so performances risk audience indifference."