Actually, it's more like 2.5 stars, since Good Reads refuses to do that half star thing. 
 Mary Russell has officially plunged into the deep end of Mary Sue with the (view spoiler)[perfect knife throwing abilities and skinny dipping parties with Sherlock Holmes. I'm now remembering why I gave up on this series back in 2008/2009. The Beekeeper's Apprentice had trace amounts of "sue-ness," (actually, quite a lot after re-reading a few weeks ago, hence taking off a star from my initial rating), but it was tolerable, and it's still a fun novel to read. However the "sue-ness" of Mary Russell progressively became worse, and after re-reading the first four books, and getting into this one for the first time, it seems to jump out even more quickly. I will finish the series, as I did stick it out for Sookie Stackhouse, another series that started out decent (entertaining, but definitely not high calibre fiction), but became laughably bad with each subsequent novel. 
 Next time anyone who claims Steven Moffat has ruined Sherlock and that Season 3 Sherlock was totally out of character, just point them to this series, because Moffat and Gatiss are far truer to the character than King. While Sherlock may (view spoiler)[shoot CAM in the head at the end of His Last Vow (hide spoiler)], it's far more in character than having a (view spoiler)[60-ish Sherlock passionately kiss a woman almost 40 years younger, and claiming that he's wanted to do that since he first met her. Extra squickiness, she was 15 at the time and was dressed as a boy. (hide spoiler)] That particular bit from A Monstrous Regiment of Women bothered me when I first read the novel, long before Sherlock was even on the air. 
 King's writing isn't terrible, it's just not Sherlock Holmes. It's only been re-reading them that they seem lacklustre, and with so many other good characterisations of Holmes out there recently, this series seems worse than it is. Perhaps there's still some hope for improvement of this series. 
 I am interested in seeing if Moffat and Gatiss do take anything from King's canon, as according to them, "everything is Canon," and they have borrowed heavily from other non-ACD versions of Holmes. (hide spoiler)]