In the play we see a few scenes showing Sandy in later life as a nun. In the film we do not know what becomes of Sandy or any of the other girls after graduation, because that is where it ends. Whereas in the book Miss Brodie is betrayed by Sandy after she and the girls have all left school and gone out into the world, the play and film put the betrayal before graduation, some weeks before the end of the school year in 1936. Sandy does it in reaction to the death of Mary MacGregor.