Interesting. I haven't read any since The God of the Hive (I think) and felt they were getting a bit formulaic. As I first read the Kate Martinellis and only started reading the Mary Russell ones when it looked like she wasn't going to write any more of those, I was also cross about the one that crossed over the two, in which Kate Martinelli had suddenly never heard of Sherlock Holmes. I like her stand-alones too and have recently re-read Folly, but I don't think I've read anything new by her for about ten years. This is a reminder that it might be worth catching up via library books.