Thursday, September 19, 1985. 7 AM, Mexico City. At the General Hospital, Dr. Ángel is handling a complicated delivery. In downtwon, Camila, an amateur journalist, is working on an independent report. In Tlatelolco, Gabriela heads to work while her husband and children get ready to start the day. The minutes slowly approach 7:19 AM... the hour that changed the course of an entire nation.

A year earlier, Camila tells her family about her dream of becoming a journalist and leaves Guadalajara. In 1985, an hour after the earthquake, signs of life are found under the rubble at the General Hospital. Gabriela, worried about her children, heads back to Tlatelolco amidst the chaos. Meanwhile, Camila discovers a group of women trapped in a garment factory.

In the 1950s, Ignacio promises his dying mother that he will always take care of his younger brother, Ángel. In 1985, two hours after the earthquake, Ángel continues his rescue efforts when Ignacio visits him. Camila encounters Gabriela near Tlatelolco, where the police are not allowing anyone to enter. Beneath the rubble, Alberto finds another survivor.

Gabriela confronts her past and the issues affecting her crumbling marriage. Three hours after the earthquake, Ángel discovers a new way to reach the babies and nurses trapped under the rubble with Pepín's help. Gabriela and Camila each make their way into the collapsed building in Tlatelolco. Meanwhile, Alberto and Regina get closer to the surface.

Some time ago, Ángel was starting a family, but the mistakes he made in the past continue to haunt him. Now, four hours have passed since the earthquake. Rescue operations at the hospital are ongoing with the help of students. Efforts to rescue survivors in Tlatelolco continue. Deep within the rubble, someone is calling for help.

For Camila, surviving and adapting to the world of news in the capital was not easy, but everything has prepared her for the present, where five hours have now passed since the earthquake. An incident involving Ángel, Ignacio, and Camila triggers a race against time to request foreign aid. The government's intentions and Ignacio's alignment are finally revealed.

Six hours after the earthquake, Chave and Pepín find themselves caught off guard by a crucial decision. In Tlatelolco, the relentless efforts and hours spent removing rubble are paying off; Gabriela and Alberto are getting closer to their children. Beto searches for a way out, while Pablo and Lucía hold on as best they can. Meanwhile, in the hospital rubble, the nurses begin to lose hope.

One year earlier, Alberto triggers a conflict with the construction company he works for, claiming that the infrastructure of his building is in poor condition. By 1985, seven hours have passed since the earthquake. Beneath the rubble, Hilda and Toña are faced with a life-or-death operation. Camila arrives at the airport, with Ignacio and Guillermo hot on her heels.

Months earlier, Lucía and Pablo fall in love during a band rehearsal, with Lucía providing Pablo refuge from his home problems. Now, eight hours after the earthquake, they remain trapped under the rubble, running out of oxygen. At the General Hospital, a miracle amidst the tragedy occurs. Meanwhile, Camila, deprived of her freedom, may receive help from an unexpected source.

In the season finale, nine hours have passed since the earthquake that shook Mexico City. Camila remains a target of the government, with Ignacio issuing orders to prevent anyone from entering the rubble, despite being so close to rescuing Rosario and the baby. Ángel faces a critical decision. In Tlatelolco, Lucía and Pablo’s lives hang by a thread, but unexpected help might change everything.