Hilda T. Shae's famous vel The Adventure League. Was the strongest selling (children's literature from 1907). The Adventure League is a children's mystery vel -- a working class friend of the upper-class Scottish kids who are the protagonists is accused of a crime that they kw he didn't commit, and they set out to prove him incent. Except that they can't do detection (like following the probable culprit to see where he goes and what he does), for it isn't horable fair play. So instead it's the story of a summer spent romping around, with the threat of their friend's fate hanging over their heads and occasional clues stumbled upon but never pursued. This classic vel is a must have for every one's library.