We found the series of "Secret Agent Jack Stalwart" from Amazon because many parents recommended it. I bought one for my 6-year-old whose English is his second language and he loved it! I tried to buy from local bookstore in Taipei but we completed the whole series from Amazon. The tools that Jack uses every time and countries he goes in every book really fascinate my son! He can non-stop reading the book and finish it in an hour then read it again and again. In the last book, Jack finally found his brother Max, it is of course a happy ending.We're glad that the commends from other parents are true, and we're happy to say it as well. Get the complete selection!