Granger is one of those paperback-original suspense writers (Gregory Mcdonald of Fletch is another) who's every bit as classy as the clothbound crowd--and it's a pleasure to welcome him to hardcover . . . even if this teasing, gently engrossing thriller doesn't ever quite deliver the dark resonance it seems to promise. Certainly the opening is sheer le CarrÃ‰: old Father Leo Tunney, a US missionary presumed dead since being captured by the Pathet Lao 20 years ago, emerges from the Cambodian jungle--a resurrection which triggers a chain-reaction of spy-world responses. Tunney, you see, was of the Vatican's espionage Order, ""the Holy Word Fathers,"" with an overlapping CIA loyalty. So both the CIA and the Holy Word Fathers (who are now up to something with the Soviets) are sure that Tunney has resurfaced with some Big Secret. Also interested: the KGB; investigative reporter Rita Macklin (whose dead brother was also an Indochina priest); and Devereaux of ""Section R"" (a CIA rival), who goes undercover to win Rita's love and trust. Thus, once the CIA has failed to extract Tunney's information, the assorted agents and Rita all converge on the US headquarters of the Holy Word Fathers in Clearwater, Fla.--where Tunney goes to recuperate, pray (in Latin, not knowing about Vatican II) . . . and write at length in a mysterious journal. Deaths ensue: the Vatican's agent is picturesquely killed by the KGB agent; the Order's chief is shot in the confessional (mistaken for Tunney). Devereaux is ordered off the case by high-up command (he ignores the order). And Rita, who inherits the journal after Tunney is himself killed, is on the run from the various powers who want the Tunney secret squelched. True, the mysteries and motives here turn out to be suitably momentous: hidden nuclear missiles, a Vatican/USSR deal, and a super-conglomerate US plan for exploiting Asian resources. But with so many subplots and protagonists (maverick Devereaux himself remains awfully shadowy), there's an increasing thinning-out of that initial le CarrÃ‰-ish texture. Still, Granger paces this cannily, slyly stretching out interest in the unknown Secret (with help from a nice red herring involving a faked miracle-cure at Tunney's Mass); and, if none of the characters is deeply engaging, virtually all of them are quietly, vulnerably likable--making this a solid, steady entertainment with more warmth than usual in the crisscrossing-spies genre.