The Secret Seven are siblings Peter and Janet, and Jack, Barbara, Pam, Colin and George. Together they are The Secret Seven - ready to solve any mystery, any time - in Enid Blyton's classic series of 15 mystery novels.
In book three, the Secret Seven have a new meeting place - a treehouse! But someone else is using it too. The gang are furious, but then they learn the intruder is in big trouble and needs their help.
Can the Seven come to the rescue?
First published in 1951, this edition features the original text and artwork.
This adventure story, featuring Enid Blyton's young adventurers - the Secret Seven - has been reissued to commemorate the centenary of the author's birth.
Enid Blyton's books have sold over 500 million copies and have been translated into other languages more often than any other children's author.
She wrote over 600 books and hundreds of short stories, including favourites such as The Famous Five,The Secret Seven, The Magic Faraway Tree, Malory Towers and Noddy.
Born in London in 1897, Enid lived much of her life in Buckinghamshire and adored dogs, gardening and the countryside. She died in 1968 but remains one of the world's best-loved storytellers.