Hurrah! It's holiday time, and the Famous Five are spending it at Billycock Hill. Most excitng 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 . . .
ISBN: 978 0 340 93174 5
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