In Who's On First, Buckley inserted CIA-agent hero Blackford Oakes into real history (the US/Soviet space race) with the cleverest sort of almost-plausibility. Here, however, the tinkering with the facts slips over the edge into oddly grating fantasy: Buckley's plot leads up to (and re-explains) the 1960 U-2 incident. . . but blithely substitutes Blacky Oakes for the never-mentioned Francis Gary Powers. How much will this annoy Oakes' wide following? Probably not too much--since overall readability is at the usual high level, with a fast-paced merry-go-round of interlocking subplots. In 1957 Blacky is dumped by the Agency for his noble yet treasonous doings in Who's On First. Meanwhile, however, the US learns that there's a "mole" in Washington, leaking minutes of National Security Council meetings to Moscow--so Blacky is re-recruited to help super-spy Rufus trace the espionage trail from D.C. to Berlin. And, also meanwhile, it's hinted that Blacky's pal/colleague Mike has, without his knowledge, a connection to the case: his Italian-immigrant father--a half-Jewish Mussolini victim and ex-Communist--is part of the spy ring. (When Mike learns the truth, he'll die to save Blacky's life--and, worse yet, someone near and dear to Blacky will turn out to be the mole herself.) Still, tracking down the spies is only the first half of the CIA/FBI/Eisenhower plan here. The second half is to use the unsuspecting spies to feed Moscow false data suggesting a Washington/Peking alliance--a decoy scheme ("Marco Polo") which must be clinched by. . . guess what? The seemingly accidental landing of a U-2 plane in Russia--a plane involved in US/China espionage and piloted by Blackford Oakes, who's nearly executed by the Soviets before they decide to trade him for the now--captured leader of their US spy-ring. True, Buckley's 1950s-minded ideological snipings (often gratuitous) are a bit uglier than usual this time around. And Blacky, so sympathetic in Who's On First, is mostly just smug, smirky (preppy-macho about sex), brave, and bland--especially when surrounded by padding concerning the U-2 technology. But even if this is perhaps the weakest (and most objectionable) of the series, it's still fast, sly, and literate: a rare, distinctive species within the lookalike thriller herd.