Whatever the story or thematic import, it was nearly a foregone conclusion that Jean-Pierre and Luc DardennesThe Unknown Girl would be a moral tale that would (a) underwhelm, (b) radiate integrity and (c) be almost entirely composed of medium shots of people talking. Plain-spoken, unforced, refined, unpretentious. The Dardennes are nothing if not consistent.

And if you’re smart, you’ll just sit there and take it. You have to slurp the soup and at least respect the ingredients. During this festival, I mean. As I wrote two years ago, the only negative thing Cannes critics are allowed to say about a Dardennes film is that it’s “minor.”

That’s certainly a fair description of The Unknown Girl, which screened in Cannes this morning. Another is CSI: Liege. Set in that allegedly dull** Belgian city, it’s about a young doctor named Jenny (Adèle Haenel) who feels besieged with guilt after ignoring an after-hours attempt by a young African girl to gain entry to her clinic. The girl is found dead the next morning, an apparent murder victim.

The film is about Jenny doing her best to investigate what happened. She is nothing if not gently persistent, and the matter is finally resolved at the end. But before it does the viewer is stuck with the unfolding, the process. Oh, the Liege of it all! That’s a cynical thing to think, much less express. But I was bored.

The root of my detachment is with Haenel, the 27 year-old winner of two Cesar awards in 2014 and ’15 (Best Supporting Actress for Suzanne, Best Actress for Love at First Fight). I look at those hazel eyes and consider her direct and plain-spoken manner, and nothing happens. Actually, something does. I realize that I’m not very interested, and that I’d like to politely excuse myself.

I realized this morning after hanging with Haenel for a half-hour that my lack of engagement was well established, and that it would take a small miracle to turn things around. But the Dardennes don’t do miracles as I define them, and so I knew I’d just have to ride it out. Which I did. I’d like credit for that.

The Dardennes are too gifted and assured and self-aware to make a poor film, but they’re certainly capable of making a lesser one. A colleague calls The Unknown Girl a “nothing-burger.”

Randomly chosen Twitter terms for The Unknown Girl: “Compassionate, plodding, dramatically stilted, well crafted, strong ending, [Haenel’s Jenny] lacks emotion and depth, unremarkable, clumsy, familiar, like a particularly weak episode of a drab CBS crime show.”

** There’s a line about Liege in Judgment at Nuremberg that I’ve never forgotten. After the court is adjourned on a Friday Judge Norris (Kenneth MacKenna) mentions to Judges Haywood (Spencer Tracy) and Ives (Ray Teal) that he’s visiting Liege for the weekend. Ives says “there’s nothing in Liege“; Norris replies that his son is buried there.