Based, according to military-fiction veteran Harris, on the papers of the late Col. Linus Iremonger of Providence, R.I.: the 1944 pursuit, from England to D-Day Normandy, of a German spy who's carrying all sorts of vital Allied secrets. The worries begin in April of 1944, when German E-boats attack a top-secret naval exercise on the British coast. (How did they know about it?!) Furthermore, among the men killed in the E-boat attack is an officer carrying super-secret D-Day-and-after plans--in papers which seem to have been tampered with. Is there a disguised German spy somewhere among the US/UK troops amassing for D-Day? So it seems--especially since three British agents have recently been murdered, all of them on the trail of a Nazi agent code-named ""the Fox."" And the higher-ups (a cameo-glimpse of Ike) now assign an odd-couple team to track down the Fox: crusty American security-officer Iremonger and prim, sarcastic British security-officer Pargeter. Together, then, with mutual suspicion (and a minor romantic rivalry) predictably turning to mutual respect, Iremonger and Pargeter go after:the Fox--who must be stopped before he can bring his secrets (the post-D-Day invasion plans, the truth about Ultra) to Berlin. They follow the master-impersonator's trail through several aliases, eventually realizing that--in the guise of an American officer--the Fox is actually boarding one of the ships headed for the first D-Day landing! And so the agents follow the spy right across to Normandy, where the Fox tries to break through to the German lines. . . while performing, ironically, a convincing imitation of an American war-hero. This finale is dark and distinctive--the spy-chasing juxtaposed with D-Day's first, grim, dirty battle. The rest, however, is mostly just poor man's Eye of the Needle: serviceable for WW II espionage fans, but with virtually no personality (the Fox remains faceless, the Iremonger/Pargeter relationship is a clichÃ‰) to enrich the rather thin chase-action.