Simon Carrerra has just been released from prison and is now on parole. His friend Albert persuades him back to his old ways with the idea of a big-time heist of a celebrated diamond in Antwerp; the "Florentine." The jewel's owner, Marie Neuville, suddenly passes away and her daughter, Julia, is left in charge of the sale. Simon encounters Julia while posing as a friend of Julia's mother. Slowly but surely, the two become closer. He manages to use their relationship to get to the diamond and the heist is a success. However, another member of the heist has a different motive and Simon has to decide if he wants to continue with the crime or help Julia recover the diamond.