Angel On Horseback Long a word-of-mouth director’s darling, Jessica Chastain finally made her name—and the awards circuit—with six films last year, including The Tree of Life and The Help. This month she stars in the Prohibition gangster drama Lawless, then debuts on Broadway in The Heiress. But what she really wants is to disappear. Listening to the 35-year-old actress spill, Evgenia Peretz discovers that Chastain’s skyrocketing career is built on fear, embarrassment, and self-doubt...Photographs by Mario Testino.