Demon Asmodeus, Lucifer's son, plays a sophisticated game of time travel. In medieval Italy, he finds the young cardinal Rodrigo de Borgia and his beloved Vannozza dei Cattanei. He decides that this couple is quite suitable for the implementation of his plans. De Borgia's name becomes a synonym for debauchery, incest and cruelty. During the war in 1945, the demon gives his favourite toy, a magical crystal, to Dmitry Malyshev. And all Malyshev's wishes come true. He returns home, marries a beautiful lady and creates an impetuous career for himself. Neither the Borgia family nor the Malyshevs suspect that not only they, but also their descendants, will have to pay a high price for all the pleasures and material benefits.