Anton Belov smuggles valuable material for jewelers - the rarest precious stones. During the last order, an attempt is made on Belov, but by chance he avoids death. Miraculously, once in Maya Maretskaya's apartment, the young man learns that Maya is an employee of a jewelry salon owned by Solomon Wehrman. Now the two of them will have to go in search of the wondrous beauty of the diamond "Little Frenchman", casually solving the failed attempt on Anton.