Tom, Peter, James, Janet, and Emily are members of their secret group, 'The Adventurers'. Together with Baxter the sheepdog, they have returned once again to solve a mystery! It is an ordinary school day at Greythorpe High School in Crawbridge, when the prized silver cups go missing. The Adventurers meet in secret to plan and begin to search for clues. What thrilling adventure lies in store for them and who are the suspects they meet? Equipped with their bicycles and whistles, will the Adventurers discover who the thief is before it's too late? Why not come along and join the children, and once again help to solve the mystery. The Adventurers of Greythorpe High have returned!