This doc seems a bit unfocused, following a variety of people living on the edges of the Parisian metropolis. It's difficult to grasp if you don't know a bit about this region, where cultural diversity is obvious but cultural mixing is not. As such, the only thread guiding the film is the commuter train RER B, which we see more or less prominently during each segment as the director follows the train line showing glimpses of locals' lives along it.
I found the film hard to follow as first, even though I come from the place featured (which helps me understand the thread of the RER, for example); the movie almost looks like a anthology film. After thinking about it however, I think it's the point: these people are very different but they barely mix, let alone know each other. Only a few connections exist between them (such as the professor who teached the director, who is herself the sister of another protagonist). Even the geographical connection, as shown by the train running in the background, is tenuous.
It's in this way that the film says a lot about "us", the French people, living as an increasingly divided society. But the connections I mentioned seem to shine a small spotlight of hope that these divides are not inevitable.
So even if the form of the film is weird and it might be hard to get into it (let alone stay interested the whole time), the image that the whole thing conveys and the message I can guess behind it are very interesting and worth a viewing.
