The Irish horror movie You Are Not My Mother introduces a compelling premise that it promptly proceeds to squander. The story is set in the days leading up to Halloween. Teenage Char (Hazel Doupe) has a somewhat fractured relationship with her sickly mother Angela (Carolyn Bracken). They have a tiff, after which Angela goes missing. Her abandoned car is found in the middle of a field. Char understandably worries, wondering if the disappearance is her fault.
A few days later, Angela returns home, with no explanation for what happened or where she was. Char and her grandmother Rita (Ingrid Craigie) notice that something is off. Angela looks okay physically, but her behavior is radically different. A sinister quality has overtaken her personality. Figuring out this mystery requires Char to dig into her family's past, where shocking secrets lie. As she does that, she additionally has to deal with being bullied by mean girls at school. And since she is by nature a timid person, neither of these challenges proves easy.
Writer/director Kate Dolan could do a lot with this set-up. Teen girls need their mothers, especially in times of personal crisis. Char doesn't have hers available, leaving her feeling adrift. That's a poignant idea. So is the thought of Char unable to connect with Angela because of this new disturbing behavior. What do you do when you no longer recognize someone you love? The family history, which provides much of the horror, could have fueled these concepts, turning You Are Not My Mother into a chiller of genuine substance. All the elements are in place.
Unfortunately, the movie simply doesn't do enough with the premise. Instead of delving into the traumatic impact of having her mom vanish, Dolan's screenplay glosses over it, spending too much time on Char getting bullied. Adding to that issue is that Angela disappears only a few minutes into the story. We barely know her when it happens. Her personality change therefore has little effect. Had we spent more time with her and been able to observe the relationship with Char in more detail, her shift would be rendered far more disturbing. Without those foundations laid down firmly, You Are Not My Mother limps forward, never generating the kind of suspense it clearly wants to.
Hazel Doupe is very good in the lead role, and there are individual moments that hold your attention, including the very unusual denouement that finds our heroine bombarded with several threats all at once. Another has Angela taking on one of the bullies. But there again, more could have been done. What if Char kind of liked her mother's newfound aggression when it benefited her? You Are Not My Mother never realizes how potentially engrossing its ideas are, and that's a real disappointment.
out of four
You Are Not My Mother is unrated, but contains adult language and violence. The running time is 1 hour and 33 minutes.