“You Are Not My Mother” is a small creepy horror film swirling around one serious family problem. Although it becomes less interesting when its dark family secret is eventually revealed during its last act as expected, it still holds our attention on what is being at stake for its main characters at least, and I enjoyed a number of quiet but disturbing moments in the movie.

After the unnerving prologue scene featuring a baby in one possibly serious danger, the movie gradually establishes the mundane and melancholic suburban daily life of an Irish teenage girl named Char (Hazel Doupe). While she is frequently ostracized at her high school as your typical loner, she does not get much affection or support at her family home, and the early scenes of the film show how much she is distant from her mother as well as her grandmother. Although she cares a lot about Char, Char’s grandmother usually maintains her reserved attitude, and we later come to learn that Char’s mother has struggled a lot with her mental illness.

On one day, something strange suddenly happens to Char and her family. Her mother is gone missing for no apparent reason, and both Char and her grandmother become quite concerned to say the least, but then, what do you know, Char’s mother soon returns with no explanation at all on what really happened to her. On the surface, she seems fairly fine, and it looks like she just needs some extra medication for treating her current mental illness, but Char’s grandmother is not relaxed at all – even when Char’s mother gladly prepares a dinner for her family.

In case of Char, she also often cannot help but feel that there is something wrong about her mother. While they remain distant to each other as before, her mother begins to act rather weirdly as days go by, and there is a chilly scene where Char happens to witness something very disturbing from her mother at one night. It is clear that Char’s grandmother knows what is really happening, and she is still not so willing to tell that all to her granddaughter, and Char naturally becomes more frustrated in addition to feeling more trapped and isolated inside her house than before.

Because of its very title as well as other similar horror flicks such as “The Hole in the Ground” (2019), you will probably not be surprised that much by what is explained later in the story, but the movie engages us more via its increasingly ominous mood surrounding Char and other few main characters around her. After another serious incident happens, the interior of her house comes to feel more insidious along with more strange behaviors from her mother, and the story eventually culminates to its expected climactic point when Halloween evening is started outside.

Although its main characters are no more than simple and broad archetypes, the screenplay by director/writer Kate Dolan, who previously made several short films before making a feature film debut here, did a succinct job of imbuing her main characters with enough details and nuances to be observed. For example, we are just mildly annoyed when Char’s grandmother made a little mistake in the kitchen, but we later come to gather that was not a mistake at all. Although the movie does not show or tell much about Char’s relationship with her mother in the past, their awkward interactions speak volumes to us about that, and we also come to understand how that eventually drives our heroine to one desperate action during the finale.

Once it shows us every card held behind its back, the movie comes to lose its unnerving ambiguity, but Dolan and her crew members including cinematographer Narayan Van Maele continue to deliver effective moments of terror as before. Although a subplot involved with Char’s several nasty schoolmates is rather contrived in my trivial opinion, that sets the ground for an intense moment of confrontation for our heroine, and this moment works better than expected despite its modest setting.

Like any good horror flicks, the movie depends a lot on the talent and presence of its three main performers, who are all excellent as subtly suggesting the darkness underneath the screen via their low-key acting. While Hazel Doupe earnestly holds the ground as an adolescent girl who must cope with many different issues inside and outside her home, Carolyn Bracken deftly balances her character between two dark possibilities, and Ingrid Craigie, a veteran Irish actress who was incidentally one of supporting characters in John Huston’s last film “The Dead” (1987), is equally solid as the other crucial part of the story.

On the whole, “You Are Not My Mother” does not break any new ground in its genre territory, but it chilled and entertained me enough at least, and some of its key moments incidentally took me back to a certain preposterous childhood memory of mine. Due to my rather complicated relationship with my mother, I often imagined that my mother was actually an old fox with nine tails which eats human liver to live more, and, to be frank with you, I was actually afraid whenever my father was absent at night. In the other words, “You Are Not My Mother” is something not so far from what I would concoct during that wild time, and I am sure that it would be appreciated a lot by my younger self.