The Clue of the Left-Handed Envelope

Third Grade Detectives #1

The detectives are on the case. What does the clue on the left-handed envelope mean? Who is sending them a message?.

Aladdin Paperbacks
2000
9780689821943
book
Lexile: 
370

Holdings

hidmidmiidnidwidlocation_codelocationbarcodecallnumdeweycreatedupdated
93287046537832191365303515034RHFY403RHFY082037FIC STA100015802161721708963493
213193956938492235365303515034HIVE259HIVE801314FIC MYSTERY STA100015825759371709307855
215191657102942236365303515034HIWA258HIWA903706FIC STA100015825759371709307855