Frances Hodgson Burnett 
Secret Garden 

First published in 1910 as a serial and fully published as a novel in 1911, this classic of English literature follows the story of neglected and sickly young girl Mary Lennox. She discovers a secret locked garden belonging to her carer, the recluse Archibald Craven, and with the help of a robin finds the key. She then works to restore the garden to its former glory.