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 close. - Ex-con is coerced into a big-time diamond heist.