A remake of Vávra's 1948 atomic age thriller Krakatit.

Soviet engineer Kuznecov is coming to Prague as an expert on work with the tunneling shield in construction of the metro. He is returning after more than thirty years. In May 1945 as a young soldier in the Red Army he was seriously injured in the liberation of Prague and while recovering experienced a great love with a young teacher called Vera.

Martin, a poor student, volunteers to go on a quest to find a cure for the princess Adriana, who is stricken with a strange illness. Unknown to Martin or anyone else, the princess is actually under the spell of the powerful magician Andlobrandini, who is preparing a rejuvenating elixir made from the blood of nine men's hearts.