Martin (M. Adamczyk), Tereza (M. Dancinger) and their son Jakub live a happy life. They have also come to terms with the boy's autism. But when Martin enrolls in school, he realises that something is wrong. He and Tereza have a different blood type than Jakub. There seems to be only one explanation - Jakub is not Martin's son, Tereza has been lying to Martin all these years. But the explanation that emerges is even worse. There was a mix-up in the maternity ward. The real son of Martin and Tereza lives in the town of Hranice in the large family of the stationmaster Karel (D. Novotný) and his wife Olga (S. Remundová). His name is Tomáš and all his relatives love him and consider him their own. Is there any right solution to this situation?

The DNA tests Martin (M. Adamczyk) and Teresa (M. Dancinger) have done confirm that Jakub is not their biological son. Tereza denies this fact. She does not want to love another child, she loves Jakub. So does Olga (S. Remundová) with Karel (D. Novotný), who, thanks to his temperament, experiences the whole situation most tumultuously. Martin and Tereza meet Olga and Karl to discuss what to do next. The meeting takes place at a motocross race, in which Tomas is also competing. No one seems to want to change anything, they all want things to stay as they are and especially the boys to know nothing. But then Tomas has an accident. Reason suddenly goes by the wayside and emotions start to drive the parents' actions.

Martin (M. Adamczyk) convinces Tereza (M. Dancinger) that he doesn't want to give up Jakub; he thinks the ideal solution would be to have both boys. Naturally, his attitude causes nervousness and tension in the family of Karel (D. Novotný) and Olga (S. Remundová). Both are afraid of losing Tomáš. Olga therefore decides to try to propose a solution that would be acceptable to both families. It seems that she might succeed. But the moment she takes Jakub's hand for the first time, everything is different again. Little Tommy finds himself in a situation he can't cope with without his mother, and Karel is increasingly angry because he correctly senses that the things that have been set in motion can no longer be stopped.

Olga (S. Remundová) and Karel (D. Novotný) have only one thing on their minds. What's next? The police intervene in the lives of both families. Reassuring the neighbourhood that it will be just routine doesn't help. The investigation into the child swapping begins and no one has the situation in their hands anymore. Not even Tereza (M. Dancingerová) and Martin (M. Adamczyk), who have to defend themselves against the accusation that they could have switched the children themselves in the maternity ward. Things get tough. On top of that, Tereza still disagrees with Martin, who wants to see his biological son Tomas more often. Karel feels the same way and doesn't want to allow any contact between them. Olga also finds it hard to bear the idea that Tomas might find out about the switch. But is it possible to keep the truth from the sons forever?

Karl is devastated by memories of his dead son Kaya. He doesn't want to lose another son and tries to find a compromise. Things are not going well at home either. Tomas finds it hard to bear the fact that Olga and Karl are not his real parents and are hostile to everyone. They are wondering how to calm Tomáš down so that he won't be afraid of having to go to other parents. Tereza wants to shut herself and Jakub in her bubble and wait for everything to blow over. But they are all due to meet at the annual celebration of the anniversary of the founding of Borders. Will they manage to tame their emotions or will the boiling cauldron explode?

Little Thomas doesn't care that the two families don't speak to each other. He wants to bring Jakub the honey that he and Uncle David dialed himself. Charles resists the visit, even shooing Tomas away from the bees, but Olga intervenes. It's not easy for her either, but if Tomas wants to, they'll go. Karel and Jakub's grandfather Rudolf can't hold back when they meet and they go at each other again. It's not just Olga or Martin and Tereza, everyone wonders why the sons were switched in these families. Why has there been tension between them for decades? But Rudolf and Karel refuse to talk...

Tereza tries more and more to connect the two families so that the sons can be together. Olga feels the same way and unknowingly helps Tereza with this. Internally torn, Tereza realizes that this is how Martin wanted it from the beginning, but she was against it. Still, she doesn't want to see Martin and only lets him go to Jakub's place when it is most necessary. Only Karl does not like the courtship of both families. He also disagrees with Olga, who promises Jakub and Tomas a visit to Karl's engineer's cabin during the train ride. Will Karel be able to resist Olga? And how will Martin behave?

Marcela hides her pregnancy, but Olga finds out anyway. That's why she's the first one she confides in. But she doesn't want to reveal who the father of the baby is. Lubos finds it hard to bear Marcela's disinterest and unrequited feelings. When he finds out that Marcela is meeting Hynek at the motocross circuit, a clash ensues. Marcela plucks up the courage to tell her dad, Karl, about the pregnancy, who addresses her brother David's newfound penchant for playing cards. He blames it on Teresa, who is surprised that David still has feelings for her many years after school. Karel and Olga throw a barbecue for friends to celebrate Marcela's baby. But only two people know that the baby's father is among them.

Even Olga notices that Jakub needs his dad and urges Tereza not to break up with Martin. Despite this, Tereza begs Karl to teach Jakub to ride a bike instead of Martin. Tereza has to admit that when she sidelined Martin, she didn't realize how hard it would be for her son Jacob to take it. When he wants to go to his dad, she can't talk him out of it anymore, and Jacob has a fit. Tereza has to go to Prague to invite Martin back to Hranice. She doesn't want to break up the family, but she also doesn't know if Martin has already decided otherwise.

Olga stops understanding Teresa's upbringing of Jacob. More and more, she feels she can't cope with Jacob's autism. But Tereza knows best how to deal with Jakub and how to try to understand him. Unfortunately, even so, she can never rule out another seizure or otherwise unpredictable behavior in public. Tereza also stifles further outbursts from Martin's parents, which Martin is unable to confront. She wants respect and empathy. Not to be criticized all the time. One more spark and Tereza can't stand to pretend that nothing is wrong.

Martin considers quitting his job in the Prague office and staying with Teresa in Hranice. But this does not please grandfather Vladimír, who fears that Martin will not stop his experiments with raising the boys. He insists that Jakub and Tomáš should have only one parent and one bed. But Olga disagrees and tries to explain to Vladimir that the more often they all meet, the better chance they have of getting to know each other and helping their sons. But Tomas wants to stay the night with Jakub. Will the families be able to cope with this new test?

Olga prepares a surprised Karl for the oddities he will have to observe during his planned visit to Jacob. Like the size of the spaghetti. Jakub is anxious and goes to see Tomas so early in the morning that he wakes up Tereza. He also refuses breakfast and waits outside with his suitcase. Jindřiška orders Rudolf and Vladimír to start talking to each other and to sort out all the wrongs. But even now they cannot find common ground. Vladimir still wants to do something. He dresses festively and walks past Jakub with his walker outside. Will he be able to reach Karl and the headmistress Katerina? And what does he want to say to them?

Jacob refuses to forgive Theresa and Martin for not being able to stay the night at Thomas' place. Tomas is also angry. In Prague, Martin pressures his parents to drop the lawsuit. He also talks to his colleague Jana. She thinks she knows who switched their children six years ago and tries to find out. Pregnant Marcela arrives home from the hospital, but everyone is on edge. The carpenter pits the two families against each other again. So they meet at the vicar's church and try to sort out their relationship for the future. But then the truth finally comes out...