The women do the heavy lifting in "Oculus," this April's "Insidious," a complex and chilling big-screen ghost story with serious movie-date potential.

"Doctor Who" alumna Karen Gillan sheds her Scottish accent and most outward signs of emotion as Kaylie, a young woman who went through something terrible and, she is convinced, something supernatural 11 years before. Now, she's out to prove that and "kill it," the thing that killed her parents and put her brother into a mental institution for more than a decade.

The "thing" that did this: an ornate, Baroque mirror, which seemed to possess her parents and, when she and her brother were little, tricked them out of destroying it.

Kaylie stares at the mirror with the look of a stone-cold killer. Or glass-breaker. She's taken a job at an auction house to get that mirror within her reach. She's set up cameras, computer sensors and timers to monitor its evil and document what she does to it.

The problem -- she's dragged baby brother Tim (Brenton Thwaites), fresh from the mental hospital, along as a witness and helper. They're back in the house where their parents died. And Tim, filled to the gills with psychobabble, sees himself as the one who "faced it," dealt with the trauma of that night with mental health professionals. To him, there is no "super" in supernatural. Just a dad (Rory Cochrane) who killed their mom (Katee Sackhoff) after she went crazy over an affair he was having.

Co-writer, director and editor Mike Flanagan structures this Night of Reckoning in parallel story lines. We have Kaylie and Tim wrestling with their past, teasing and tormenting the haunted mirror, goading it to kill again. And we have them as kids -- fearfully played by Annalise Basso and Garrett Ryan -- terrified as their family explodes, forced to be "really brave" to face what they cannot fathom.

Gillan handles the film's exposition, a long, breathless narration-on-camera that tells her brother and her video audience the tortured history of this mirror, whose victims mutilate themselves and then kill before they themselves are killed. That's the dull part of "Oculus."

The exciting stuff comes from Kaylie -- brave, then and now, trash-talking the mirror, touching its crack and purring, "I hope it still hurts."

And Sackhoff, of "Riddick" and TV's "Battlestar Galactica," makes the most of her motherly descent from suspicion to paranoia to madness, selling this far-fetched fantasy, start to finish. She renders this plausible.

It's not a contest, but the guys are good and the women, to a one, much better in this chiller. The effects are modest and affecting, the pacing not quite as brisk as you'd like and the finale entirely too predictable in this age of franchises. But "Oculus" earns its frights the old-fashioned way -- with convincingly traumatized characters, with smoke and with mirrors.

'Oculus'

* * ½

Rating: R (terror, violence, some disturbing images )
Cast: Karen Gillan, Katee Sackhoff, Annalise Basso, Brenton Thwaites, Rory Cochrane, Garrett Ryan
Director: Mike Flanagan
Running time: 1 hour, 41 minutes