Possible Clues:

• Retribution of no concern to a good GP? (1,5,2,4,3,8)
• The returning of the treatment one has given others (1,5,2,4,3,8)
• Payback: just what the doctor ordered, to some extent (1,5,2,4,3,8)
• Harsh treatment as revenge (1,5,2,4,3,8)
• Treatment received as revenge for similar treatment (1,5,2,4,3,8)
• With which one gets paid back dissolved association endowment fee (1,5,2,4,3,8)