The story is about a high-school soccer-player suicide, which, of course, quickly turns out not to be a suicide. Yoann Peeters (very well played by Yoann Blanc), in this small town after a case that went very bad in Brussels, catches this investigation. The local police are mostly earnest, somewhat bumbling, and by-and-large competent. Suspects are manifold, and the narrative develops with lots of twists and turns and surprises. [From here on there'll be lots of spoilers, so read on either if you don't care or have already seen the series.]
The power of the narrative comes from the likely and unlikely suspects who are revealed and then turn out, for one reason or another, not to have done the deed. This is the part of the story that makes it a top-notch, powerful whodunnit.
But a story like this requires an equally powerful, plausible ending. And though the end is powerful, it opens up a huge pothole in the plot. Inès, Yoann's high-school sweetheart (he grew up in the area), is a great choice for the villain, since that delivers such an emotional punch to Yoann and the viewers. She's been Yoann's lifeline for a lot of the story, resisting his entreaties to get back together again at first, and now that they're together again her revelation as killer is emotional dynamite.
But ... why would she, as the killer, have been the one to show Yoann, early on, that Driss (the victim) couldn't have written the suicide note, since he didn't have the written skills? Wouldn't Inès have wanted the case closed as a suicide, as soon as possible?
We could come up with reasons - Inès felt guilty, she wanted Yoann to investigate the death because she loved him and thought Yoann's active investigation was the best way of keeping him around - but we shouldn't have to come up with motives like that, especially when there was another, much better, candidate for the killer, the police chief, who indeed did do his best at first to close the case as a suicide.
But The Break is nonetheless a riveting 10-episode series, and well worth your viewing.