Story : The third episode of SuperQuark opens with a documentary from the fantastic BBC series A Spy in the Pack and this time hidden cameras will spy on dolphins. We went to take a closer look at the world of this marine mammal, one of the most fascinating and intelligent creatures in the animal kingdom. For the first time we will be able to follow them in all their adventures thanks to special video cameras applied to underwater devices capable of very rapid movements that seem like fake fish and can therefore secretly film their behavior, rarely observable until today. Why do potholes form in the road surface and are there no techniques that allow you to lay out pothole-proof asphalt? Superquark went to investigate the physics of potholes, with a report and then with Paco Lanciano and Piero Angela in the studio. Alberto Angela will take us along the Aurelian Walls. With their route of over 18 km, they are the longest and best preserved ancient city wall in the world.