The Gerasimov family is large and close-knit. Pavel, an architect and father of five children, dreams of having a sixth. The only thing standing in the way of their happiness is the cramped Moscow apartment they live in. Inspired by this pain, Pavel develops a residential complex for large families called "Kovcheg" (Ark). The idea of the project appeals to the developer, Lev Borisovich, but only as a way to attract attention. This puts Pavel in a difficult dilemma: to increase his living space by deceiving others in similar situations, or to confront a very powerful person. The family realizes that they are not capable of making deals without a conscience, so they sell their apartment and leave the city. They settle in an old house where Pavel's ancestors lived and decide to build their own "Kovcheg" with their own hands. This choice turns the family's life into a real adventure, revealing the power of a large, close-knit family and each of its members individually.