Triangle is a 2009 psychological horror film written and directed by Christopher Smith and starring Melissa George, Michael Dorman, Rachael Carpani, Henry Nixon, Emma Lung, and Liam Hemsworth.

The film was based in part on the story of Sisyphus, the Greek mythological figure cursed to repeatedly push a boulder up a hill without ever successfully reaching the top.

Smith insisted on having a set constructed that depicted the exterior of a cruise liner, in order to minimize shooting in front of green screens.

Jess is spotted after she drops her keys near the display case, and she attempts to warn the second Victor when he chases her, only to accidentally impale his head on a wall hook.

She takes a shotgun and confronts the second group, intending to "change the pattern", but a third Jess, repeating the loop, kills the second Greg and Downey and severely wounds the second Sally.

She distracts her counterpart with the doorbell, then kills her, puts the bagged body in the car trunk, and leaves with Tommy, vowing to him that things will change.

[4] The film is based in part on the story of Sisyphus, a figure from Greek mythology cursed to repeatedly push a boulder up a hill without ever successfully reaching the top.

The writer-director wanted to maintain the link and, to do so, baptized the housing estate where Jess lives "Sunshine State", a nickname used by locals to refer to Queensland.

As for the auditions, the director has revealed that he chose Melissa George for the lead role after seeing her in the television series In Treatment, where she plays a young woman who feels a deep attraction for her psychotherapist.

To edit the sequence in which the camera passes through the mirror "following" the actress, Smith acknowledged having been inspired by one of the final shots of The Woman in the Window, by Fritz Lang.

Icon Home Entertainment released Triangle on DVD and Blu-ray in the UK on 1 March 2010, with features including a commentary track by director Smith.

The site's critics' consensus reads: "Triangle sails into some strange waters, but this intelligent, well-acted horror outing anchors its idiosyncrasies in a satisfyingly scary story.

[14] Time Out London reviewer Nigel Floyd praised George's "fearless, credible performance" that "grounds the madness in a moving emotional reality".

[16] Fellow Guardian critic Peter Bradshaw wrote that Triangle is a "smart, interestingly constructed scary movie", complimenting Smith for "creating some real shivers".

Although he praised George's acting, he wrote that her performance "can't shield the fact that this still an exceptionally non-scary horror, that will have you scratching your head more than jumping out of your seat", ultimately rating it 2/5 stars.

[18] The Scotsman called it "a trickily plotted and slickly made effort that nevertheless can't quite make its premise fly in gripping enough fashion".