Peter and Jack fall out, and Jack says he's leaving the Seven. But no one wants him to go and Peter sends Jack an apology. But Jack sends a letter back to Peter saying, he is forming his own club with, Susie, Binkie, Bony and three others, and they'll be the Secret Seven and you'll be the Secret Six! But then valuable dogs start to go missing, and the thief appears to be a large person according to his footprints. But whilst the Six are investigating, Scamper goes missing too. Hearing this news Jack wishes he was part of the Seven and helps by making an amazing discovery!