After 30 years of teaching in London, Mark Thackeray retires and returns to Chicago. There, however, the challenge of teaching kids in an inner-city school proves to be too much to resist.After 30 years of teaching in London, Mark Thackeray retires and returns to Chicago. There, however, the challenge of teaching kids in an inner-city school proves to be too much to resist.After 30 years of teaching in London, Mark Thackeray retires and returns to Chicago. There, however, the challenge of teaching kids in an inner-city school proves to be too much to resist.