Jem and the Mystery Thief — Susan K. Marlow

Jem can't wait for school to let out for the year. Is there anything more boring than class when you could be outside? When rich boy Will brings a coin collection to school, it's an exciting treat. It isn't often the students get to see all that interesting money in one place.

Then a silver dollar goes missing during recess--and Jem is blamed! After all, he's the only one who went indoors on this sunny day. When a charm bracelet is stolen the next day, more fingers point his way.

Jem knows he isn't the culprit. But how can he prove it? To clear his name, Jem sets a trap for the mystery thief--his sister's gold locket lays in plain sight on his desk as bait. Will it go missing too? Or will Jem's good name be muddied forever?