The Defenders

For eight years humanity has lived underground while robot 'leadys' fight the war on a radioactive surface no person could survive. Don Taylor, a weapons planner on his first rest period in months, is happy to read about another raid on Moscow over breakfast, while his wife Mary tries not to think about the surface at all.

Then Taylor is summoned to first stage, the level closest to daylight. A leady brought down for interrogation has just tested stone cold, without a trace of the radiation it describes in every report. Security wants answers, and for the first time since the war began, a party of humans is going up the Tube to see the surface with their own eyes.