Unimaginative, slow-ish, but solid WW II espionage--with a Nazi spy in America going after the A-bomb secret (yes, once again, folks). . . while the FBI is close on his trail. The faintly sympathetic German is physics-trained Baron Joachim von Niehauser, a blue-blooded patriot and Eastern Front veteran who sneaks, via submarine, onto the Maine shore in 1944; his sniveling sidekick is a US Army deserter. And, thanks to this creep/ coward, von Niehauser winds up committing several murders en route to N.Y. (the sidekick himself is one of the victims)--killings which attract the attention of moody FBI agent George Havens. Havens almost nabs von N. in New York; he then teams up with the Army (who have realized that von N. is heading for Los Alamos) to track down the spy. Meanwhile, von N. is killing his way across country: his mission, you see, is to meet up with refugee-scientist Erich Lautner (a Los Alamos insider who's a secret Nazi spy), learn the A-bomb secrets from him, and get them both back to Germany via Mexico. But, while Havens is trying to anticipate that Mexico escape-route (a Mexican tycoon is involved), ambivalent scientist Lautner is having an affair with Jenny, the wife of a Los Alamos security officer. And so, when von Niehauser does arrive, things get very messy: the security officer is killed; the two Germans and Jenny flee; Havens pursues; Lautner is killed; Jenny is stuck with the kamikaze super-spy; and there's a wilderness/ordeal showdown between Havens and von Niehauser. A sliver of Eye of the Needle-style tension here and there, some sturdy action--but, with underdeveloped character relationships (Jenny is an especially ill-managed creation), this is so-so suspense at best, less entertaining than the most recent steal-the-A-bomb novel, Ben Stein's The Manhattan Gambit (p. 29).