She rushed out of her bedroom, yelling, 'THIEVES! ROBBERS! COME QUICKLY!'

Big Hollow is a mysterious and brooding place, where the Famous Five are camping out. Nearby lives a famous scientist, and one night some top-secret papers are taken from his house. But they were hidden high up in a tower, which is impossible to reach! How could they have been stolen - and can the Five find teh thieves the secrets are revealed?