The novel begins with Tatsuya Asakura, manager of the planning and general affairs section at the S Heavy Industries
Tokyo Headquarters, as he has an unusual experience returning to Tokyo on the
Tokaido Shinkansen. Communications and traffic within Tokyo suddenly stop, and the
Shinkansen stops at
Hamamatsu Station. Here, Asakura meets his friend,
JASDF officer Sakuma. At 7:00 AM that day, a cloud with a 60-kilometer diameter radiates from the center of Tokyo, completely enveloping the city to a height of 1,500 meters. Gozo Otawara, an advisor to S Heavy Industries with PHD's in science and engineering, works with the Central Research Institute of S Heavy Industries and Jonan Medical University to investigate the cloud where Yokohama New Road crosses National Route 16. Tamiya, a classmate of Asakura's and editor-in-chief of
Kitakyushu's local newspaper
Seibu Shimpo accompanies the investigation. The cloud is discovered to consist of water vapor and high levels of ozone and argon. It resists all attempts to penetrate it, including bullets. Humans cannot walk more than 20–30 meters inside before being stopped. Radio waves also don't reach inside the cloud, so the condition of Tokyo's inhabitants is unknown. That evening, at the
Atsugi base near the Central Research Institute, an emergency meeting is held between the Self Defense Force and US Forces stationed in Japan, involving United Nations and Ministry of Foreign Affairs representatives. The US forces stationed in Japan urge the Japanese to rebuild the government as soon as possible. Tamiya, inspired by the seriousness of the situation, travels to the
Kansai headquarters of A Shimbun and works to rebuild the Japanese government. 10 days after the cloud's appearance, an emergency national governor's conference is held in
Nagoya, establishing
Hyogo Prefecture Governor Komuro as the temporary chief representative. The organization is formed by a coalition of
prefectures and ordinance-designated cities. It consists of prefectural governors, deputy governors, prefectural assembly chairs, mayors of ordinance-designated cities and representatives of Tokyo,
Kanagawa and
Saitama prefectures. The basis for legal legitimacy is emergency evacuation under international law, with the premise that the Japanese government is out of touch, but still in existence. Simultaneously, the cloud begins emitting powerful
particle beams, damaging or destroying any aircraft or satellites passing above it. An
EP-3E reconnaissance aircraft is directly hit by a particle beam, destroying all electronic equipment and killing one crew member from radiation exposure. The United States researches the cloud's abilities for military purposes, while the
Soviet Union detains a Japanese diplomat to increase external pressure on the country. In January of the following year, the Soviet Union sends a large fleet to
Hokkaido. A huge earthquake occurs off the coast of
Nemuro, and the Soviet fleet is destroyed by a
tsunami. At the end of March, about four months after the cloud's appearance, an international survey of the cloud is conducted. It is determined that the cloud is an automated surveillance device sent by intelligent extraterrestrial life. Shortly afterward, in early April, the cloud disappears as suddenly as it appeared. == Release ==