Three naval cadets accidentally get possession of a secret diary that was stolen from Bestuzhev, a vice-chancellor of Russia. If this diary ever gets abroad, the consequences for the country would be grave. The cadets are trying to return the papers to their owner, but there are others who want to get the papers...
In the second movie the Naval Cadets are guarding the princess coming from Germany to marry a Russian prince.
There is a seven-year war, Russian soldiers are forced to fight for the interests of France and Austria against Prussia. The midshipmen continue to selflessly serve the Motherland. One is on an expedition, the other is at court, and the third is sent to Venice to hand over a jewelry box. In fact, there is a message in the box, on which the future fate of Europe and Russia depends!
