An artificial intelligence device threatens a family in this movie from the director of ‘About a Boy’ and ‘Operation Finale.’

HAL, that sentient computer in 2001: A Space Odyssey, has a lot to answer for, not least the flood of lesser demon-computer movies that have followed in the decades since.

Weitz did have the good judgment to cast John Cho in the lead. Cho has become expert at playing worried dads. In Searching (2018), he used social media to hunt for his missing daughter. Here he plays Curtis, who actually brings the demon-AI into his home, where he lives with his wife, Meredith (Katherine Waterston), and their three children, and where it will monitor every second of their lives.

But Weitz never ramps up the tension. As the pros and cons of using AIA play out, we see the danger without feeling a shred of fear. Meredith is won over because AIA can help with everyday chores like ordering groceries. Their 17-year-old, Iris (Lukita Maxwell, the daughter on Shrinking), is skeptical at first too, but is swayed after AIA cleans up a deep-fake porn that used her face, and that AIA itself probably created and spread online. AIA helps the middle child, Preston (Wyatt Linder), with his anxiety, and reads stories to seven-year-old Cal (Isaac Bae).

It’s telling that Curtis says early on, in too-heavy foreshadowing, that being a parent is terrifying because, hard as you try, you can’t always protect your children. AIA becomes a sinister stealth parent, creating secrets with the kids. She gives Preston extra screen time, overriding the limits on his iPad. She tells Curtis and Meredith she will show the children a documentary, then shows The Emoji Movie instead. While the movie plays and the parents are getting some time alone, they are unaware that AIA has crept into the laptop in their bedroom, as she will in every phone and device in the house.

Throughout, even after Curtis and Meredith realize something is wrong with the whole intrusive experience, Cho and Waterston have little to do beyond looking worried. Waterston has one big, effective scene when AIA, in a desperate attempt to keep her on board, creates a virtual version of her dead father. Cho goes to the company’s headquarters and tries to smash AIA’s mainframe hardware with a baseball bat. But as almost everyone knows — and the fact that we know this makes the story beyond ridiculous — smashing an actual device hardly matters when everything lives on the cloud.

Afraid never really explores the issue of AI, and as a flat-out attempt at horror it doesn’t have to. But it should at least be scarier than real life.