Motivated by a climate emergency, researchers have begun in recent years to explore Earth’s great ocean currents in depth. Through satellite imagery, soundings from thousands of profiling floats and computer models, these currents are gradually revealing their astonishing complexity. As we learn more about microscopic marine life, responsible for more than 50% of the oxygen we breathe, we are realizing that these organisms are closely linked with the movement of ocean currents. Featuring scientists from around the world, this well-documented film explains the influence of the great ocean currents from a new angle while providing an update on recent discoveries. The quest involves a major challenge: to decipher the workings of this enormous machine and enable us to predict rapid and possibly radical changes in the conditions for life on Earth. Discover the great ocean currents, a fascinating and complex world on which the future of humanity depends.