Hurrah! It's holiday time, and the Famous Five are spending it at Billycock Hill. Most exciting of all, they've made a new friend - a real pilot! But now he has disappeared, with top secret equipment . . . The Five are puzzled, and concerned, too. Could their new friend by a spy - a traitor! Whatever his motives are, the gang feel duty-bound to investigate . . .

Enid Blyton, who died in 1968, is one of the most popular and prolific children�s authors of all time. She wrote over seven hundred books, which have been translated into many languages throughout the world. She also found time to write numerous songs, poems, and plays, and ran magazines and clubs.