About a third of the way through the supernatural thriller “Slumber,” a sleep researcher named Alice Arnold (Maggie Q) receives a mysterious note with only the word “nocnitsa.” Like anyone in that situation, Dr. Arnold quickly looks up the word on Wikipedia. It’s an honest moment, but also unintentionally funny, given that “Slumber” itself feels like it was loosely adapted from a few cursory Google searches.
“Nocnitsa,” it turns out, is another word for “Night Hag” — the ancient name for a demon that torments people suffering from sleep paralysis. As seen in the 2015 documentary “The Nightmare” (and a number of old paintings), some people can hover on the line between consciousness and unconsciousness for an uncomfortably long time, experiencing terrifying hallucinations.
Maggie Q gives an engaging performance as Alice, who reluctantly revisits mysteries from her youth while helping a family tortured by their own dreams. Director/co-writer Jonathan Hopkins guides the entire cast well, making a movie that’s polished and assured throughout.
But while all the technical jargon and historical context lend an air of sophistication, ultimately “Slumber” is just another generic possession movie, following a handful of ordinary folks whose troubled pasts come back to haunt them — literally. Hopkins and company don’t bring much special or personal to the material.
The plot’s predictable and the shocks are routine in “Slumber.” And no amount of hastily appended footnotes can change that.
Rating: R, for some disturbing material, and language
Running time: 1 hour, 24 minutes
Playing: AMC Citywalk, Universal City