The film begins in the 1980s Soviet Union. Two best friends, Orlov and Muravyev, are serving at the Black Sea Navy Base in Sevastopol, Crimea. Both fall in love with one beautiful girl Nelly, and their friendship suffers a first blow. Because she picks Muravyev, his friend Orlov struggles with an inferiority complex and becomes a secretive alcoholic. After the collapse of the Soviet Union in 1991, both friends are transferred to the Northern Fleet on the Polar Ocean. One day their sub is performing a routine training. A disturbed WWII mine slowly moves on a collision course with the sub. A mighty blast knocks down everyone inside the wrecked sub, 72 meters below the sea level. Then ensues a nerve-racking struggle for survival.

A unique ring has been stolen from the Hermitage! A rare artifact that has been passed down from generation to generation of the imperial dynasty has disappeared! A detective agency, 'Michelle,' has taken on the search. However, they face unprecedented pressure. It is at this point that a true journalism ace, paparazzo Yegor Leonov, gets involved in the investigation. For him, this is a way to earn money, as it is already known that General Burlyaev, criminal authority Vasily, and monarchist Prince Sokolov are involved in the theft! The main task for Yegor and the staff of the 'Michelle' agency is not just to find and return the ring to the Hermitage, but to do so discreetly. After all, the loss of such a rarity could cause an international scandal!

The main character is Viktor Shtrum, a talented Soviet physicist who refuses to blindly follow his "comrades" by signing false documents and becoming a tool in the hands of an all-powerful state. During the war, Shtrum’s mother, Anna Petrovna, was sent to a concentration camp, but her letters continued to arrive for many years and help him remain more moral than those around him.