Story : Two gunshots, in a castle a few steps from Vienna, in Mayerling. To erase the memory of that night, the place was transformed into a convent, but it has become a place of pilgrimage for those who still remember the end of Sissi's son: Rudolf II of Habsburg. Piero Angela reconstructs this story, telling a love story, that between Rudolf and the very young Mary Vetsera. But also a particular moment in European History, between intrigues and power games, against the backdrop of the Imperial Court of Vienna. The story, which shook public opinion at the end of the nineteenth century, sparked the imagination of many novelists and directors in the following years. Historians have questioned themselves and lined up on different fronts, because Rudolf would have been the heir to the throne of the most important empire in Europe, the Austro-Hungarian one. His tragic death was intertwined with the events that led to the First World War and perhaps changed the balance of power in Europe.