The series has eight episodes, describing the seven critical days of panic after the nuclear disaster in Japan. It starts from the perspectives of the government, enterprises and the risk-taking personnel on the scene, and through rigorous data collection, it truly restores the incident and tries to answer a question: "What happened that day?" At 2:46 pm on March 11, 2011, a magnitude 9 earthquake occurred in Kurihara City, Miyagi Prefecture, Japan, with a maximum intensity of 7. The area within 130 kilometers of the Sanriku coast was severely damaged. Many islands in Japan turned into ruins. An hour later, a 15-meter-high tsunami rolled up in the sea and instantly engulfed the Fukushima nuclear power plant, but that was just the beginning of the nightmare. The earthquake caused the cooling system of the nuclear power plant to fail, and the situation was completely out of control.