I very much enjoy The Martini Club characters. I love reading stories that have characters over 40 because it makes it much more relatable to me. I also enjoy Jo, the other main character, who is not over 40 but she is very likeable. 
Tess Gerritsen's writing is always fabulous. She does a great job of setting the scene, describing the characters and drawing you in. There were plenty of twists that had me guessing along the way. I was not seeing that outcome so well-done! I thought it was someone else completely!
I would not recommend this as a standalone. It would help to read the Spy Coast first so that you understand the characters more.

I am so looking forward to number 3 in the series!

Thanks very much to Netgalley and Thomas & Mercer for an advance copy of this book.