A cat wakes up in an over-water world where all human life seems to have disappeared. He finds refuge on a boat with a group of other animals. But getting along with them proves an even greater challenge than overcoming his fear of water! From now on, they'll all have to learn to overcome their differences and adapt to the new world they find themselves in.

In a middle school at the foot of Mont Blanc, SEGPA students have no interest in anything. To motivate them and make them dream, Alain, their teacher, organizes a surprising and perilous outing into the bowels of a glacier. The teenagers discover a breathtakingly beautiful world of ice. But they realize that with global warming, if nothing is done, this glacier like many others could disappear. Against everyone's advice, but led by their teacher, they throw themselves heart and soul into a crazy project: to protect the glacier and stop it from melting... From now on, nothing can stop them, because there's no Planet B!