Ulisse will dedicate this episode to the First World War, making us relive one of the greatest tragedies of all time which cost the lives of millions of men. It was a different war from those that had preceded it. Together with conventional weapons and traditional warfare techniques, new technologies took to the field, increasingly powerful and increasingly ruthless: the machine gun, the first tanks, submarines up to perhaps the most frightening weapon of all, gases and chemical warfare. Alberto Angela will go to the trenches of the Carso and to the tunnels of Monte Sabotino where thousands of soldiers died between 1915 and 1918 and, directly from the places where the fighting was fought, he will tell us the motivations and the most salient episodes of this war; where the soldiers came from and how they were recruited, their life in the trenches, their anxieties, survival strategies, the weapons used and fighting techniques.