What if a teacher s most promising pupil is also her most dangerous? A tautly plotted psychological thriller, as intelligent as it is mesmerizing "What Has Become of You" follows Vera Lundy, an aspiring crime writer and master of self-deprecation who, like many adults, has survived adolescence but hasn t entirely overcome it. When she agrees to fill in for a private school English teacher on maternity leave, teaching "The Catcher in the Rye" to privileged...