Five Go Off to Camp (The Famous Five #7)

The five go camping in a moor with Mr Luffy, a master at Julian and Dick's school. When they arrive at the camp they find that their camping site is close to a farm, and that several old train tracks run under the moors, some of them are unused. They soon make friends with a boy named Jock, who lives at the farm with his mother and stepfather, the farm owner. While exploring the moor, the five find a railway yard and a tunnel that are apparently abandoned. Spook trains in the dead of night! And they seem to vanish into thin air - but where do they go? The Famous Five are on to it! But the unusual discoveries have made them puzzled. If they follow the tracks, will they solve the mystery?