Horror is evolving as a genre. Although your local multiplex is still loaded with the usual contenders, look a bit closer and you’ll find the latest drama, thriller, or crime offering is closer to horror than you might expect. In this bi-weekly series, Joey Keogh presents a film not generally classified as horror and argues why it exhibits the qualities of a great flight flick, and therefore deserves the attention of fans as an example of Not Quite Horror. This week, it’s Unforgettable.

Sometimes horror creeps into mainstream cinema slowly, subtly, in a veiled reference to Cannibal Holocaust midway through an adventure movie, or in an unusually gory death sequence during an otherwise mannered portrait of a family in crisis. Others, it presents itself as an unhinged Katherine Heigl, starring evilly across the street at Rosario Dawson without a shred of irony.

Unforgettable is the latest erotic thriller to bother multiplex audiences, hot on the heels of art-house masterpiece The Handmaiden. Of course, producer-turned director Denise Di Novi isn’t nearly as interested in female sexuality as Chan-wook Park. Her focus is on the dangerous games women play in the service of dull, bland men called Jake or Mike. Or, in this case, David.

Rosario Dawson and Katherine Heigl in UnforgettableHow David ended up with Heigl’s obviously mental Tessa is of little consequence in a film where she glides about in a floor-length white gown, brandishing a massive kitchen knife, like the ghost of bloody (literally) Christmas past. This is the kind of movie where everybody behaves like they’ve never seen a horror flick.

Theirs is a world in which a smart, independent woman like Dawson’s Julia keeps the fact she has a murderous stalker from her new love because…it might worry him? It’s a world in which, in spite of acknowledging how loopy his ex is, David still refuses to believe Julia when she’s spinning out of control due to being openly harrassed by her.

Unforgettable takes its horror cues from the most maddeningly over the top and bludgeoningly obvious fare, with a sudden screech of violins reminding us to be scared before a dark figure darts by the window. In its best, most unsettling shot, an innocent party guest morphs into Heigl’s villainess as she turns to narrow her eyes in Julia’s direction.

Horror fans will be put off by the curious lack of blood once the stabbing begins, especially considering it takes place on a white carpet–the most perfect canvass for the red stuff aside from a blanket of fresh snow. Its R rating (15A in the UK) hardly seems necessary given how low on gore (and, indeed, sex) it is, with the most shocking scene suggesting masturbation.

Katherine Heigl in UnforgettableFilms like Unforgettable make one appreciate just how hard the majority of horror movies work to wrong-foot and unsettle us. Unlike an erotic thriller that earns the second part of that description, like Fatal Attraction, there’s no real suspense to be mined from Julia and Tessa’s relationship. The latter is clearly unhinged from the moment we meet her.

This does allow for some cracking, and completely ludicrous, scenes of sabotage, however–particularly when Tessa uses some dodgy websites to, essentially, steal her love rival’s identity. That none of this lunacy is possible hardly matters. The salacious edge to these sequences elevates Unforgettable to almost-amazingly-terrible status.

If only it went fully-fledged psycho, it might be one for the ages. A future contender for How Did This Get Made? for sure.