Today, 1/3 of the world’s population suffers from a lack of fresh water. In 2025, it will be half. Are there any viable solutions? 3,000 meters below the surface of our planet lurk massive reserves of fresh water known as aquifers. They are 30 times greater than all of the fresh water that exists on the surface of the earth, yet barely exploited. Alain Gachet, a mineral engineer, has come up with a cutting-edge technology that allows to locate fresh water in Earth’s deepest substrata. Following his indications, UNESCO has managed to build drilling stations around the world, already providing hitherto unsuspected fresh water to hundreds of thousands of people. Our film follows Alain as he explores the sources of «invisible water» in two of the world’s most water-stressed areas today: Kenya and Iraq, where hundreds of thousands of refugees have fled the ISIS conflict. By uncovering the potential «goldmine» that these deep fresh water sources represent, the film also reveals the economic and geopolitical issues at stake. Could aquifers be an efficient solution to the world’s water crisis? It may be a drop of water in the ocean of global warming issues… but it’s a drop of drinking water.