The Changeling, Robin Jenkins

Thirteen-year-old Tom Curdie, the product of a Glasgow slum, is on probation for theft. His teachers admit that he is clever, but only one, Charles Forbes, sees an uncanny warmth in his reticence and in his seemingly insolent smile—so he decides to take Tom on holiday with his own family. This powerful novel explores one of Jenkins's consistent and most fruitful themes—how goodness and innocence are compromised when faced with the pressures of growing up and becoming part of society.