A century of scientific discoveries has led us to the infinitely small: the 20th Century was the Microworld era, a world we still live in. Despite the spectacular leaps in science, despite technological progress brought to everyone, today this world has reached its limits. Perhaps it was simply a step towards the world of tomorrow, the 21st Century: the Nanoworld. How? Why? This episode introduces us to researchers who have understood how to observe and manipulate the nanoworld – these atoms like bricks constituting our universe.