Off the Rails — Anne Rooney

Can two boys solve a mystery they were never supposed to know about? 

 

Karl is on the train going home from school when he sees two men dumping a rolled up carpet into a ditch. Karl notices a scruffy shoe sticking out of one end. After telling the police, who don't seem to be that interested, Karl drags his friend Daniel to the ditch to investigate further -- but they are soon disturbed by two unsavory characters.