A strange and deadly mist envelops Paris. A group of survivors finds refuge on the upper floors of apartment blocks and on the roofs of the capital. With no information, electricity, food or water, a couple attempts to survive this disaster and save their daughter… But as the hours go by, one thing becomes quite clear: there is no help on the way, and if they want to make it through this catastrophe alive, they will have to try their luck in the mist…

It’s the end of the school year. The long-awaited moment of the holidays is arrive. The little Nicolas, her parents and Grandma take the road towards the sea, and settle in for some time at the Hotel Beau-Rivage.