This book. This book is the reason to read the five books that preceded it.
Gamache has been called to a dead body in the basement of the Literary and Historical Society, the repository of English speaking history in old Quebec. He begins to question the ending and conviction at the end of the brutal telling, and sends Jean-Guy back to Three Pines to see if he can dig up anything new. And something has happened, between books 5 & 6 that is hinted at through flashbacks. Something horrifying and terrible, and members of his team are dead. Gamache himself nearly died. Jean-Guy nearly died.
Penny manages these disparate strands with aplomb and sensitivity, letting us feel with Gamache, in retrospect, the horror as the event that has killed the youngest and newest member of his team unfolds. We learn, slowly and through a glass darkly, what happened as he tells us, mimicking what it felt like to be investigating a disappearance of a member of the homicide squad in real time, as members of the team scrambling frantically to find out what has happened, and what the purpose behind the kidnapping could be. And we see him try to heal, both physically and emotionally, from something truly terrible and personal.
One of the things that I love about Penny's series is that she has avoided the trope of the bitter and cynical detective. Inspector Gamache has not hardened his heart to world, it is bruised and battered, but he still loves and believes in the value of what he does as a murder detective. He is open to people, and that openness is one of the qualities that makes him a great detective. He dares to care, knowing that at the end of caring there might be a broken heart.
History is woven through this book and through this series. The murder of the hermit was a result of history, personal and long gone. The murder at Lit and His library was because of history, and the battle for the soul of Quebec. And the terrible incident reflected to us in flashback was because of history as well.
The final reveal of all of it is almost unbearably tender and painful. A requiem.
"The past is never dead. It's not even past."