Original French title: "Les canal des secrets." Another episode of the French TV series "Murder in ..."
This one starts with a tourist boat entering a gorgeous lock in the canal. Inevitably, there's a corpse floating in the lock. We get a bit of an intro to the history of the canal as exposition from one of the police officers. As most of the events take place near the canals, this one is rife with travel porn (although, like previous ones, the compression on the DVD is high which makes it all chunkier).
This is one of the ones where the officer's lives, problems, and disagreements are front and centre, with both our lead police having significant personal issues. I prefer the ones where it's mostly about the mystery and less about their lives. And there are a bundle of red herrings, although they turn out to be pretty plausible. To the writers' credit, all the personal problems they bring up have a fairly direct bearing on the case: in the end, I was okay with it.