I am now waiting for the last two instalments, but straight from the first episode, it looked to have a very familiar to feel to it, and I rapidly developed a feeling that this was French TV's answer to the US series, "LOST", with both series being riddled with the inexplicable. Both series even have their own mysterious clouds, though in Lost, it was more like black smoke.
Of course, unlike Lost, this is not set on a desert island, but what looks like the South of France. That tends to make me raise questions, such as why are there no old or fat people to be seen.?
And then there is a plot line that if true, would have the whole town besieged with the world's media. yet there is no media presence at all. The unlikely events that take place, include a lighthouse being moved from offshore to a mile inland. If that can't get a few TV cameras interested, then nothing can, and yet there is no media. Where are the Politicians from Central Government, who you might normally expect to be giving unhelpful interviews?
The whole story lacks the infrastructure that one might expect if such an event ever were to happen.
Reverting back to my comparison with Lost, that was a series that I enjoyed for about the first five seasons, and I looked forward to all the mysterious events being explained. But as it continued, I got to the stage where I lost interest, and can't even be bothered to find out what happened. With that in mind, if the series ends and I have to wait for season two (3? 4? 5? 6? etc), I won't bother. The comparison is that both series are highly implausible and so you want to see the final episode to make sense of it. But I am not that interested that I am going to wait years for an explanation.