Hardy Boys: Secret Files, Books 1-3 by Franklin W. Dixon (Paperback)

In Trouble at the Arcade, nine-year-old Frank and eight-year-old Joe Hardy discover trouble lurking at the local arcade and decide they make pretty good detectives—just like their dad!

In The Missing Mitt, the boys must help their teammate find his lucky mitt before the last game, or their Little League season is doomed!

In Mystery Map, nine-year-old Frank and eight-year-old Joe Hardy get their hands on a piece of a treasure map. But they’ll need to work with their friends and hunt down the rest of the map in order to have a chance at finding the treasure. Let the sleuthing begin!