Five Go to Billycock Hill
Enid Blyton
 Camping again, this time on Billycock Hill, near the farm of Toby, a boy from Julian and Dick's school. Toby was very proud of Jeff, his cousin and thought he was a hero.When Toby's Cousin Jeff, a British Air Force pilot, flies off late in a stormy night with the newest aircraft made by British army which is full of secrets. The five are stunned. The media tells that the Jeff has flown away and people in the world too think Jeff is a traitor.Could Jeff really be a spy? But the five and Toby don't think he is a traitor. Will the famous five solve this mystery?