Solve the mystery with the Secret Seven - everyone's favourite detective club! These timeless stories are perfect for young fans of mystery, adventure or detective series. Also available in audiobook!
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?
Solve the mystery!