A massive, fascinating and thoroughly unsettling history of Russia's infamous gulags by Anne Applebaum, noteworthy for its expansive view, effortless prose and prodigious research. Instituted in the aftermath of the Revolution and expanded during the reign of Stalin, this system of prison camps was simultaneously the Soviet Union's darkest secret and their greatest industrial asset. Millions died and millions more slaved in mines and factories. Winner of the Pulitzer Prize.  (SIB34, $18.95)