The Murder of Mary Russell by Laurie R. King

Welp, I'm all caught up on this series now, as this is the most recently published book. I've been working on catching up on some favorite series in the lasts couple of months, & I've made progress on Three Pines (one remaining book), Sebastian St. Cyr (two remaining books), and Ruth Galloway (caught up).
I'm not sure how many more Mary Russell books are likely to be written - it feels a bit like Ms. King is coming to the end of the natural lifespan of the books. As the series matures, I admit to be terrified at the prospect that she will, sooner or later, kill off Holmes.
However, I will continue reading them as long as she continues writing them.
This book is, of course centered around "The Murder of Mary Russell." I don't want to spoil anything for those of you who haven't read it, but
(show spoiler)
It focuses us on Mrs. Hudson, the landlady from 221B Baker Street and surrogate mother to Mary Russell. In this book, Laurie King takes one of the stories from the Adventures of Sherlock Holmes, IV. Gloria Scott, and she unravels it like an old sweater being remade, reknitting it with the same yarn, but in a pattern that reveals much more than the original, and that provides the backstory for Clara, nee Clarissa, Hudson. Much more than even The Moor, The Murder of Mary Russell goes back to the roots of Holmes and takes the interstices of the tale and fills them with detail and life. I had never read Gloria Scott, and when I read it after finishing this book, the weaving of the new story out of the old tale was fairly brilliant.
I don't think I've ever read the entire Holmes canon, and reading this reminds me anew that I need to do that sooner, rather than later.