The history of life on Earth and that of fire are intimately linked: volcanism is at the origin of the formation of the first organic molecules and the appearance of life on Earth.

In Alaska, the fresh water that feeds the rivers comes from the snowfields of the highest mountains in North America and the most active volcanoes. When a volcano erupts, the river poisons the fish. Scientists are trying to understand what may have happened more than 2000 years ago and are trying to find an answer to the salmon's specific behavior: return to their native river when death approaches. On the way to an extraordinary epic.

Directors: Bertrand LOYER, Jacques BEDEL and François de RIBEROLLES