Christmas is coming. The children accidentally break a Nativity scene figurine from their father's collection and must by all means get an equal one, the problem is that it is a unique antique piece. Sara, the eldest daughter breaks up with her boyfriend, Ocho, who will try to recover her favors with the help of her father-in-law, Javier. Precisely Javier's father-in-law, Marisa's father, will be welcomed into the family home to spend the holidays after her recent separation, which will not leave Javier's mother, Milagros, indifferent. Rocío, the folklore of the family, who has been playing the Virgin for several Christmases, is relegated this year to playing the shepherdess, something that her father, Javier, is not willing to assume.

The eldest of the family, Sara, comes of age and brings chaos to the family by announcing her intention to marry Ocho. Javier and Marisa try to avoid it at all costs. At the same time Dani has an existential crisis, Paulita feels jealous of Cris, Carlota announces that she has found a boyfriend from a high society family and Rocio has finally managed to be cast in her first film.

The success of the Conchy virtual assistant (which was developed by Javier) has earned him a favorable spot in the parents chat room - until something unexpected ruins it all.

Javier is what we have dubbed as a "husband-in-law." That is that without taking care of the care of the house and children at all, he knows exactly what needs to be done, and that he continuously collects a sum of sentences from the type: "It is that you do not organize", or "do not get nervous", you already consider that overflowing woman drowns in a glass of water. Javier will have to face the reality of dealing with five children (between four and twelve years old) when his wife decides to go on a trip and leave him alone with them. The chaotic situation that takes place at home will progressively evolve ecologically to the most absolute disaster, but at the same time it will give parents and children the opportunity to meet and enjoy themselves for the first time.