Level 7 is a 1959 science fiction novel by Mordecai Roshwald. It describes the experiences of a soldier, X-127, who is ordered to push the button to begin World War III, and his remaining life and death as the radioactive fallout from above eats its way slowly down into his underground radiation shelter, level by level.
Level 7 was adapted by J. B. Priestly for a 1966 episode of the BBC2 television science-fiction drama programme Out of the Unknown.
See also: apocalyptic science fiction