Day of Judgement

From the back cover of Bantam paperback June 1980:

June 26, 1963. JFK's triumphal visit to divided Berlin is about to trigger catastrophe for the Free World... East German Intelligence -- with the aid of a renegade American -- has set a diabolical snare. And now, only a desperate team of Allied operatives -- six monks, an American priest, a British major and a young woman doctor who has played into Communist hands -- can save the West from a terrifying DAY OF JUDGMENT