A haunting evocation of the fire-and-ice political partnership between Robert and John F. Kennedy—and of how, despite energy and idealism, the brothers encountered tragedy by blundering into “a trackless wood of ambition and emotion.” Bobby was protector, prod, and conscience to his brother—and, he came to fear later, the unwitting agent of JFK’s assassination, according to Mahoney (JFK: Ordeal in Africa, not reviewed), a former John F. Kennedy Scholar at the Univ. of Massachusetts and the Kennedy Presidential Library. The brothers gave a hint of their later relationship in the 1950s, when Jack coolly served on the McClellan Committee investigating corrupt unions while Bobby, as committee counsel, pursued Jimmy Hoffa. While Jack provided the savoir faire, Bobby supplied the moral passion and energy. The brothers shared a disregard for risks that they inherited from father Joe—who, Mahoney alleges, secured the Mafia’s financial support and vote-getting strength in Chicago at a crucial juncture in the 1960 presidential campaign. But as attorney general, Bobby launched an assault on the underworld, hoping not only “to rid the country of its pernicious influence, but also to sever its connection to the Kennedy family,” in Mahoney’s words. Compounding the Mob’s rage was the fact that the administration was simultaneously employing kingpins like Johnny Rosselli in Operation Mongoose against Fidel Castro. Mahoney has assiduously plumbed a host of sources to re-create the web of circumstance that put the Kennedys in the sights of their enemies (who also numbered J. Edgar Hoover and, after the Cuban missile crisis, anti-Castro rebels). But he’s particularly eloquent in depicting the later Bobby: suspicious that the CIA or its minions had killed his brother, then redirecting his crusading energies away from the personal vendettas that may have boomeranged against Jack and toward impassioned advocacy of blacks, migrant workers, Native Americans, and anyone at the margins of society. A graceful dual biography that demonstrates why the questions lingering after their murders are as enduring as the Kennedys” magic.