Louise Penny said this quote
“ When Olivier had been taken away Gamache had sat back down and stared at the sack. what could be worse than Chaos, Despair, War?What would even the Mountain flee from? Gamache had given it a lot of thought.What haunted people even, perhaps especially, on their deathbed? What chased them, tortured them and brought some of them to their knees? And Gamache thought he had the answer.Regret. Regret for things said, for things done, and not done. Regret for the people they might have been. And failed to be.Finally, when he was alone, the Chief Inspector had opened the sack and looking inside had realize he'd been wrong. The worst thing of all wasn't regret. ”