The book was written by Frances Hodgson Burnett and is about a little girl called Mary Lennox who was born in India to wealthy parents. Mary's life in India comes to an end when her parents die as a result of an epidemic in India and she goes to live with her uncle, Archibald Craven, in England.
One of the maids in her uncle's house, informs her of a secret garden where her uncle's late wife spent a lot of time in until her untimely death in the garden. As a result, Archibald Craven had the garden locked up and constantly mourns his wife.
However, Mary finds a key to the garden and takes her uncle's son (her cousin) to the garden to help him improve his health and be happy once again. As a result of his son's improved health, Archibald Craven rejoices in the secret garden with his son and niece and is happy once again.