The history of the intelligent Demin family begins in the distant 60s at a dacha near Moscow. In the center of the plot is housewife Lidiya Sergeevna, her husband Georgiy Vasilevich - a design scientist, son Slava - a student at the rocket science department, and daughter Tanya - a beautiful and smart young girl. Lydiya is preparing to celebrate her birthday in a warm family circle, as they have always celebrated for many, many years in a row. However, her plans collapse as soon as she sees that her son Slava arrived not alone, but with a nice girl Zoya, to whom he proposed right at the family holiday. Mom immediately noticed that the young lady was simple-minded and not from their circle. But sweet Zoya has turned into a real antagonist for Lydiya, from whom it is impossible to get rid of, like in a nightmare. But the problems of the mistress of the house began to grow like a snowball: the newly-made daughter-in-law turns out to be pregnant and lies about her family, her husband calls her graduate student "beloved," her promising daughter runs away from home, and there are "skeletons in the closet" of Lydiya herself, which she kept for a long time , become known to everyone. A tight knot of problems unravels completely unpredictably, dramatically and unexpectedly, tearing off masks, exposing the truth, drawing more and more new characters into the whirlpool of events.
