Wildly contrived Nazi/IRA suspense--with all plottings arranged so that Grant (Moscow 5000) can keep hopping to and fro between 1940 and 1980. Bestselling writer Prof. Thomas McBride arrives in 1980 England to research Churchill's secret 1940 operation called ""Emerald Necklace."" What was the plan? No one seems willing to provide the real answers--and then Thomas discovers that his own father was working with WW II British Intelligence on this very plan! So--flashback to 1940, as Michael McBride travels the Irish coast, attempting to unravel the secret of ""Emerald Necklace."" And the rest of the novel switches back and forth, with considerable padding and implausibilities used to delay the final revelation of the big secret: Hitler and Ireland had conspired in a plan to make way for a German invasion across the channel--but Michael McBride (whose father-in-law was in the IRA) caught on to this scheme, thus making it possible for Britain to hatch a counter-scheme involving both the total destruction of the U-boat invasion force and the Anglo-American naval disaster needed to push Roosevelt into joining the war. (The Emerald Decision is Churchill's yay or nay on this operation.) Meanwhile, back in 1980, a major peace negotiation between Britain and Ireland is being planned--which will be disrupted if the IRA gets its hands on the embarrassing Emerald Necklace secrets. So: lots of racing about, falling bodies, plus an unconvincing love affair for Thomas with the Irish-Marxist daughter of the man who shot his father--a festival of gimmicks and coincidences and blather (""A curious sense of predestination assailed him, almost as misty and illogical and assertive as a religious experience"") that does provide a modicum of page-by-page suspense until sheer nonsense ultimately takes over.