Possible Clues:

• Incidental benefit
• Plot trails for each Parisian who expected tip
• Bonus for each is accepted by all
• Agent upset somewhat about his initially denied fringe benefit
• A rather round one's a bonus
• Fringe benefit for each is brought in fairly
• Incidental or casual benefit
• Incidental benefit for each is put in fairly
• Tip is queer, queer tip
• Extra benefit for each is brought in fairly