The Mystery of the Scar-Faced Beggar (The Three Investigators, #31)

Wanted: one scar-faced beggar who dropped his wallet. Wears dark glasses and a grimy jacket. Last seen outside a bank — just as a daring robbery began inside!
The Three Investigators are eager to find this man. They're sure he was a lookout for the robbers. The young detectives have a clue to where he lives — but no idea that he'll lead them onto a trail of terror!