Pro-Nazi activity in late-1930s Britain is intriguing, relatively fresh thriller territory; but first-novelist Irving hardly gets much mileage out of it in this cluttered, episodic mix of romantic suspense and fictionalized history. Irving's hero is intelligence man Edward Seton, who's working virtually solo, often at odds with the higher-ups as he keeps an eye on Nazi sympathizers among the horsy set. And heroine Ruth Seton is an irritatingly naive U.S. woman who falls for dashing pro-Nazi Lord Dunsinnan--with whom she travels in Germany (Lord D. is cozying up to various biggies there)--but finally switches allegiance when Lord D.'s lethal bigotry surfaces, as does Seton's passion for Ruth. But, aside from Ruth's growing awareness and Seton's growing suspicions (a fishy death at the Dunsinnan estate, Dunsinnan's secret list of pro-Nazis), Irving has no genuine central plot moving through the novel's first half; he concentrates instead on a semi-fictionalized treatment of the government's doomed Nazi policy (exaggerated fear of the Luftwaffe, appeasement, failure to support anti-Hitler factions in Germany) and on myriad guest appearances by the famous: Hitler, Lloyd George, Burgess and Philby, Canaris, Heydrich, Churchill, Joe Kennedy, pro-Nazis Lady Astor and Lindbergh and Unity Mitford. Thus, the interplay between fact and fiction up to 1940 is sometimes provocative, more often just vague and confusing--and then, apparently aware of the novel's listlessness, Irving crudely changes his approach and tacks on the tale of the reputed Nazi attempt to kidnap the Duke of Windsor, here with Ruth and Seton on the Duke's trail around Europe. (Irving's Duke is clearly pro-Nazi, as opposed to the noble Duke in Harry Patterson's version of the same material: To Catch a King, 1979.) There are a few cheaply effective ironies along the way, a few competent scenes, and a dense though disjointed dramatization of some rich history', but the glaring lack of focus and the weak characterization here make for choppy and grab-less reading, a disappointing treatment of a fascinating milieu that journalist Irving should perhaps have presented in non-fiction form.