Good Work, Secret Seven by Enid Blyton
The Secret Seven haven't had an adventure for ages, so they get busy making a guy for Bonfire Night instead - even though Scamper very nearly ruins it. But all their plans change the very next day. Peter and Janet are dozing in the back of their father's car when two strange men jump in and drive it away! Peter and Janet stay safely hidden in the back - and as soon as they can they escape and get the Seven together to work out how to track down the thieves. But they quickly realise they're on the trail of a dangerous gang, and suddenly they don't feel quite so brave...Have the Seven taken on too much this time? And can they stop the men before they carry out their criminal plans? Enid Blyton is one of the best-known and best-loved authors of all time. In polls, she is consistently voted a children's favourite, and over a million of her books are borrowed from libraries each year. She wrote over 600 children's books, including the bestselling Famous Five and Secret Seven series.