Blyton, Enid <br/><br/>
Five go off to camp 

 - London  Hodder Children's  2001 
 - 250 
 - The Famous Five .
<br/><br/> 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 discovery of an unusual underground tunnel system, and a secret train-service, has them puzzled. If they follow the tracks, will they solve the mystery? 
<br/><br/><label>ISBN: </label>9780340796214 
<br/><br/><label>Dewey Class. No.: </label>823  / BLY-F