Recommendations based on "The Famous Five and the Mystery of the Emeralds A New Adventure of the Characters Created"

'This summer the Five will become six--and George isn't happy about it. American girl Berta has been threatened with kidnap, and Kirrin Cottage is the only place she can hide. But Berta's arrival puts them all in danger when someone starts spying on them from Kirrin Island. Berta may be in disguise, but can they keep her safe and protect her from the kidnappers?' -- Back cover.

Solve the mystery with the Secret Seven - everyone's favourite detective club! This fantastic bumper collection contains Secret Seven books 1-3, with illustrations by Tony Ross. Book 1: The Secret Seven (first published in 1949) It's their first adventure and the Secret Seven super-sleuths are already on the trail of a mystery! The gang are dressed in disguise, following a lead to a spooky old house in the snow... Book 2: Secret Seven Adventure (first published in 1950) When a priceless pearl necklace goes missing the Secret Seven are first off the mark to catch the thief! Why? Because they saw him making his escape! Now all they have to do is find the necklace ... Book 3: Well Done, Secret Seven (first published in 1951) 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 ...? These timeless stories are perfect for young fans of mystery, adventure or detective series.