Hillenbrand's second book, seven years in the making, is "Unbroken: A World War II Story of Survival, Resilience, and Redemption" and likely to be as big a hit as "Seabiscuit." The theme is identical -- the triumph of an indomitable underdog in the face of titanic obstacles -- but this time the protagonist is human: Louis Zamperini, an Olympian in his own right (he ran in the 1936 games in Berlin), war hero, POW camp survivor and inspirational speaker. [. . .] Those hopes were, of course, pulverized by the outbreak of war, and Zamperini became a bombardier in the Army Air Corps, stationed in Hawaii. The book's exciting descriptions of foot races give way to even more exciting accounts of bombing raids and airborne battles. [. . .] Zamperini and Phillips' luck ran out when, while on a rescue operation, their plane conked out and crashed at sea. Only the two of them and a third serviceman survived, floating on rafts through shark-infested waters...