The film tells the story of the Shendelev family, whose work is closely connected to the underwater world. For them, it is not just a job - it is a matter of the heart with a mission: to make the Baltic Sea, one of the most polluted environments in the world, cleaner and more alive. At the bottom of the sea lie not only sunken ships and planes, but also thousands of lost fishing nets - the so-called "ghost nets", which silently kill fish, seals, birds and other marine inhabitants. The family and their colleagues dive into the depths to find these nets and bring them to the surface. Their daughter Valentina follows in her parents' footsteps, but is still searching for her place in the world.