The Castillo family returns home for Christmas after working all year for ADN. They are exhausted but happy to reunite with Mario and Dora, who have left the academy. Even before arriving home, they must act in the subway to stop a pickpocket without revealing their powers. They attend Dora’s school play, where the girl suffers bullying from some classmates and ends up using her electrical powers in an uncontrolled way. The family has to clean up the mess: erase recordings and the memory of a teacher who saw everything. Rosa Ruano, wanting to help Borja in his new job as a police officer, tries to make a good impression on his boss, Otero. She and her partner Nacho investigate a strange case related to the Christmas toy of the moment: the “Trickster Elf.”

Agent Otero continues investigating the case and discovers the true identity of the Castillo family; according to police records, they disappeared 15 years ago. Even though internal affairs does not allow it, Otero decides to take charge of the investigation with Nacho’s help. Julia, Mario, and Lucía carry out a plan to manipulate Otero’s mind so she begins to doubt what she actually saw. The problem is that the video recorded that night is going viral, and even Dora and her parents have to flee an ice rink when everyone starts recognizing them. The news also reaches ADN, and Dante urgently brings them back to the academy and imprisons them without mercy, just as Max is spreading his hatred and causing children to violently attack their parents. They must escape, or Christmas will be in danger.

Blanca and Jimena explain to the Castillos that they have been hiding from ADN for a long time, but have decided to come out of hiding because Blanca, in one of her visions, has seen that something terrible will happen this Christmas and only they can stop it. However, they cannot leave their refuge because the police are searching for them, nor can they use their powers because they know Dante would detect and locate them. So they consider their only option to find Leo and go back in time to fix this entire mess. But things do not go as planned and they end up trapped. On top of that, Dora begins to be controlled by Max’s evil power.

A year ago, Max was not the villain he is known as today; he was just an innocent child who discovered that he had powers and could control people’s will. His mother and her then-partner, a petty thief, took advantage of him and forced him to commit horrible crimes that ultimately marked him and turned him into what he is now. At that time, Sandra and Culebra were considering having another child; Lucía broke up with Cala after discovering his infidelities; Otero arrived new at the police station after being demoted and began investigating the strange cases in which Max was involved; and at ADN, Rosa Ruano’s retirement was being celebrated while someone with hidden interests was covering up Max himself.

The story continues where it left off in episode 3, with all the Castillos trapped and Mario in mortal danger from an evil Dora who is being controlled by Max. Dante, Julia, Otero, and Paqui work together to save the Castillos, and they plan a strategy to stop Max and prevent Christmas from being lost. When things get complicated, Blanca appears and prevents a disastrous outcome, managing to ensure that Sandra and Culebra’s baby is born, though not without difficulties, and bringing the family a new power.