A book by a young man who escaped a life of slavery in the Sudan was bought by St. Martin's editor-in-chief George Witte. It's Escape from Slavery: The True Story of a Modern-Day Slave's Escape from the Jihad by Francis Bok, who was captured as a child and lived a life of endless cruelties before he was able to get away, eventually to the U.S., where he now works for an anti-slavery group in Boston, drawing attention to the continuing existence of slavery in the Arab world. Witte preempted for world rights from agent James Levine and plans to publish next spring.