Meet Peter, Janet and Jack, Barbara, Pam, Colin and George. Together they are The Secret Seven - ready to solve any mystery, any time! Book 7: Secret Seven Win Through. The Seven have a fantastic new hiding place. But someone else is using it at night - and it's Jack's little sister Susie who helps them catch the intruder. Book 8: Three Cheers, Secret Seven. Peter and Jack see a gas-fire alight in one of the rooms when they search for their lost aeroplane in the garden of an abandoned house. Who is hiding there and why? Book 9: Secret Seven Mystery. A girl runs away from home - and it's up to the Seven to find her! Jack's little sister Susie is up to her usual tricks - but she can't put the Seven off the trail of clues!