Buckley's best Blackford Oakes thriller, written seemingly by a new William F. Buckley--abstemious, ambitious, inoffensive, hardworking. It is, perhaps, his subject that has leveled Buckley's usual roseate gaiety, for here he wades into the shadows of the Kennedy assassination and gives us a somber eye throughout. Not that a basso profundo death-note is struck truly, but we do see Blacky reeling. Among other shocks that Blacky suffers is the defection of his longtime bedmate Sally Partridge: while Blacky is in midassignment, setting up Operation Mongoose in Miami and Cuba, she marries a wealthy Mexican! Blacky, sent reeling, sails solo into the ocean, where he's so besotted with sadness that he can't even swill the fifth of gin he's brought along but just sips a beer or two. Meanwhile, he's trying to focus on Attorney General Robert F. Kennedy's direct order to him: assassinate Fidel Castro. Though Blacky is the leading character, he often fades from view as Buckley hops about various sites of villainy in Cuba, Mexico, Miami, and Moscow, giving a very big picture whose storm center eventually becomes Castro's anger when two assassination attempts against him fail, and he decides to lend his enthusiasm to Lee Harvey Oswald, who has come knocking on his door. At the same time, Castro has a hidden Soviet missile aimed at Dallas, which he plans to launch if Oswald fails--all of which places Blacky in the most excruciating double bind of his career. . . Mid-brow melodrama that is a strong recovery after Buckley's recent Blackford Oakes blandishments--and far more gripping than his twitterings as bon vivant of the high seas.