Funny how Kaylie Russell (Karen Gillan) is only able to trace the seemingly indestructible antique she blames for the death of her mom and dad as far back as the 18th century, and to the Scottish royal family's country estate. This becomes a convenient means for the makers of Oculus to completely evade having to explain how a wall mirror became the locus of supernatural activity, maliciously driving a mother to drown her tots, causing a fat man to lose weight before driving him to suicide, and convincing Kaylie and her brother Tim's (Brenton Thwaites) parents that their marriage was being torn apart by another woman. Take, though, the entity's absurdly elaborate sense of humor, and strange propensity to cause dehydration, as a given and the film may be enjoyed as a throwback to such low-rent, psychologically charged chillers as Sandor Stern's Pin, another slow-burning yarn about siblings tormented by a maybe-not-so-inanimate object.
In Oculus, seeing isn't exactly believing when Kaylie and Tim reunite with their antique mirror for a final showdown, and the film is at its nerviest when foregrounding the object's taste for blurring the lines between the real and the imagined. Tim enters the fray as a doubting Thomas, and with an irritating litany of psycho-babble as a means of explaining the horrors of the past away, but Kaylie quickly makes him into a believer with newfangled recording devices and a plethora of iMacs, which first capture the pair having discussions in contexts in which they weren't originally delivered. As plants wither around them, the brother and sister are cruelly teased with the possibility of having done harm to themselves and to others, from a shard of pottery driven into a loved one's neck to a bite taken out of what may not actually be an apple. And it's with these did-I-or-didn't-I horrors that the stage is set for what becomes a grippingly staged time warp.
Oculus begins in dreams before freely hopscotching between Kaylie and Tim's present-day sleuthing and the horrors that, 11 long years ago, sent her to foster care and him to a mental institution. Through a mini-triumph of montage, what begins as run-of-the-mill backstory vomit is thrillingly repackaged as an almost-Lynchian duet between warring states of consciousness. The mirror, as it tightens its grip on the brother and sister, forces them to waltz alongside their younger selves during their parents' last days, and subsequently the depth of the siblings' fraught relationship to their shared past is put into poignant focus. The final shocks may completely unhinge from Kaylie and Tim's troubles with memory and foreground all the supernatural hooey that's so dubious about the story to begin with, but until then, director Mike Flanagan's keying of his formalist frights to his characters' subjectivities makes Oculus both a scarier and wittier haunted-house attraction than James Wan's The Conjuring.