This is the second book in the quartet about Paul Brodie and Shane Kingslake.
Now Brodie is lured from his Himalayan valley to penetrate a secret Soviet nuclear establishment in the Ukraine, where they are testing the effects of radiation on human guinea-pigs to measure the effects of radiation; Brodie is blackmailed by his spymaster, Cready-Smythe, into taking the assignment only because his friend, Alex Guthrie, who had saved his life, is now a prisoner in the centre.
Brodie is captured and subjected to mental and physical torture. However, he escapes and mines the reactor with explosives then threatens to blow it up thus and contaminate a whole Ukrainian river system and the countryside.
He contrives not only Guthrie’s escape but saves the sixty-odd prisoners of the establishment.