"The Secret of Gioconda: Diary of a Thief" is an exciting novel by the Austrian writer Ernst Bernhard Josef Theodor Schwitzky, which tells the story of a professional thief who decides to steal Leonardo da Vinci's famous masterpiece - the painting "Mona Lisa". But his plans are ruined when he learns the secret behind the smile of the mysterious woman in the painting. This book captivates the reader with intrigue, mysteries and unexpected turns of events, revealing the secrets of great art and the human soul.