Possible Clues:

• Unpaid companion in a biblical city
• Lay person
• "Rank" novice
• There's no accounting for his performance
• A friend goes to old city with one without expertise
• Hustler's target
• Unskilled ship's officer visiting a Babylonian city
• No expert, but someone of a mature disposition
• Any Olympic athlete, once
• Hornung's cracksman presumably unrewarded