Moscow banker Denis receives a mysterious call from his old friend Charles, an employee of the Unclaimed Deposits Department at the world's oldest bank, Monte dei Paschi di Siena, where an unclaimed 18th-century deposit of 20,000 gold louis d'or, made by the Maltese knight Blaise Marie de Aydi, was discovered. Today, this sum is worth over 10 million euros, and according to the will, the heirs of the princes Cherkassky can receive it. Denis and Charles decide to find the descendants and receive two million euros for their services, but soon discover they are not the only ones hunting for this deposit.