[1][2] Marcos Novoa Pazos (Martiño Rivas) and Paula Novoa Pazos (Carlota García), two Galician siblings whose parents have disappeared on the high seas, go to El Internado: Laguna Negra under the custody and guardianship of the director, Héctor de la Vega (Luis Merlo).

The girls tell Iván Noiret León (Yon González), Roque Sánchez Navas (Daniel Retuerta), Cayetano Montero Ruiz (Fernando Tielve) and Marcos, who go to meet Alfonso, but he ends up not being there.

The death of Cayetano has further awakened the interest of the boys to know who is behind all the strange murders committed in the boarding school, especially for Roque, a faithful friend of the deceased and supposedly the last person he spoke with.

At the same time, a new, somewhat troubled student, Julia Medina Jiménez (Blanca Suárez), comes to El Internado after having had a romantic relationship with her stepfather.

Vicky has other matters to attend to since Cristina Palacios, a girl from her neighborhood, disappeared without a trace and thinks that the new teacher is the culprit.

Elsa Fernández Campos (Natalia Millán) is pregnant with twins and discovers that she has a twin brother who is lost in the forest, but through the memories of Jacinta García Aparicio (Amparo Baró) It Is shown that a young Jacinta (Carolina Lapausa), hid him in the past to protect her life and he is the Gnome, a friend of Paula.

The boys think that Hector is the culprit of everything, but they realize that this is not true when they find out that he belonged to the group of orphans who, like them, investigated what was happening there.

And on the other hand, Toni Fernández (Alejandro Casaseca), Iván's biological father, who comes to clean the kitchen chimney and stays as a technical repairman.

Rebeca will feel an attraction towards Martín, who looks embarrassed since she sees the darker side of someone just by touching him, and she saw him kill Don Joaquín.

But he does not believe and insists on removing Samuel, Marcos and Paula's little brother, and his wife Sandra Pazos (Yolanda Arestegui) from the place where they are kept.

In addition, a capsule of a deadly virus has spread for the boarding school, because of Javier Holgado (Sergio Murillo).

All end up infected and without medicines, when they discover that everything is in the hands of Ottox and that Colonel Araujo is in command of the quarantine, he is actually Karl Fleischer, one of the Nazis and founder of the Gemini project.

Four new people enter at El Internado, they are infected: Clara Sáez de Tejada (Natalia Lóz) the old dance teacher who works for Ottox, Curro Bermúdez Pereira (Eduardo Mayo) he was looking for Amaia González (Nani Jiménez) when she was infected, Javier Holgado's mother and another boy who has not yet been known.

In the final chapter of the series, everyone is cured of the virus with the machine that Max Levov (Santi Pons) builds, who is killed by Amaia, who dies when she tries to take Paula and Vicky hits her head with a shovel and when she falls she throws a syringe with some deadly material, he actually only had air the same way he killed Max.

Fermín dies in the arms of María, assassinated by Lieutenant Garrido, but his death has not been in vain since everyone leaves the boarding school thanks to his escape strategy.

Finally, the military realizes that Lieutenant Garrido is with the Nazis and allows the students to cross the fence and leave the boarding school.

The Nazi founders who were left alive; Colonel Araujo, Theodora Raüber and Lieutenant Garrido are arrested by Rebeca and the military.

This reboot also works as a direct sequel since in the first chapter we are shown a sequence from a newscast where Julia Medina Jiménez (Blanca Suárez) and Iván Noiret León (Yon González) are in an interview with Sandra Sabatés talking about the book they wrote together where they tell everything that happened to them and their friends in the “Laguna Negra” and the book is dedicated to their daughter Carolina Noiret Medina who was named in honor of their old friend Carolina Leal Solis (Ana de Armas).

The series began its first season (with 10 episodes each 50 minutes long) in November 2009 and ended in December of the same year due to results beneath what was expected.