E.L Konigsburg

Poor Little Rich Boy Winston Carmichael has it all: a big house, servants, vacations in Palm Beach, and a fancy private school. But with overprotective parents and a sense of responsibility for his younger sister, Heidi, Winston sometimes feels more as if he's living in a prison than a dream. Then one day a woman appears at the front door claiming to be Caroline -- Winston's half-sister, who was kidnapped and presumed dead long before he and Heidi...