Note- I received a digital ARC of this book in exchange for my honest review.
I am a longtime fan of this author and series, so I was chomping at the bit to read the latest installment. My first impression reading was that it was a bit of a departure for the series- Russell and Holmes were a bit more openly expressive towards each other than normal and their conversations with each other felt a bit different. The crime/central mystery didn't appear until about a third of the way through the book, and even then didn't provide many twists and turns. Mrs. Hudson plays a big part in this book and I will be honest and say I'm not really invested in her- I like the character well enough but am not that interested in her goings on at this point.
I love Russell and I felt that this book was a very enjoyable time spent with her and provided I think a good, believable insight into how she is changing and growing emotionally as she is now 25.
As a standalone book I would probably give this 3 stars- the story isn't great, but Ms. King is a great writer so even without a great plot she can really keep a reader engaged. As part of this series with established, rich characters that are built upon here though I give it an easy 4 stars, and am now chomping at the bit to read the next one!
Anyone considering reading this book I highly recommend starting from the beginning of the series and working your way forward!

I was given this book by NetGalley for an honest review -
Mary Russell and Sherlock Holmes arrive on the Riveria.
A friendship forms between Sara, Gerald, & Russell.
Russell is investigating their former housekeeper who hasn't been seen since she was accused of murder.
And then a man is found dead in the housekeepers room.
Those who control the casinos don't want the investigation
Can Sherlock and Mary solve this?

Mary Russell returns (with Sherlock) in another exciting adventure. We get to see some familiar faces and an interesting peak at historic figures. There are a few surprisingly sweet little moments and lines that remind us that this is a marriage, not just a partnership, but it is primarily with keen minds, solving the puzzles life throws them.

Riviera Gold equals the quality that all its sisters in the Mary Russell series show. Witty, sincere, and delightfully academic, fans new and old are sure to love Mary Russell, Sherlock Holmes, and a rather cunning Mrs. Hudson in Monte Carlo.
The great part about King's series is that she loves to play "historical character sardines", with the next book including one (or two or five) more nonfictional people than the last. The crossovers add a realistic feel to the fictional characters and a flair of make-believe to the real-life.
King provides a satisfactory conclusion to character arcs that will leave you asking, "How could I have thought anything different?"

Riviera Gold picks up shortly after the previous book and longtime fans of the series definitely won’t be disappointed with the 16th book in the series!

Continuing to look into Mrs. Hudson’s past into present, this is classic Russell and Holmes at their best. The storyline and twists and turns are as well written as always, with some surprises but also wraps up nicely. The characters were introduced to were interesting and added to the overall story. Loved it!

Fans of this smart, sophisticated series will not be disappointed in this 16th installment, which finds Mary Russell and Holmes in the midst of a mystery that centers around Mrs. Hudson's flight to Monte Carlo and the subsequent murder of a young man in her new home. Holmes and Russell encounter exiled Russian arms dealers and smuggled treasure as well as Lily Langtry and Pablo Picasso. A lot for one book, but author Laurie R. King is a master at blending these engaging fictional characters with real historic personages and events while also respecting the Sherlock Holmes cannon. Nevertheless, while Holmes is important to untangling the mystery, the emphasis is very much on Mary Russell. Events unfold through her keen, observant eyes as she occasionally defies Holmes in deference to her friendship with Mrs. Hudson.

Full Disclosure--NetGalley and the publisher provided me with a digital ARC of this book. This is my honest review.

The 16th! Chapter of Mary Russell and Sherlock Holmes begins almost right after Island of the Mad ends.
Mary Russell is heading into Monte Carlo, Monoco and connects with old and new friends. As always there is danger, history, excitement and a vivid picture of 1920's Monoco. Everything ties up nicely, and I love the connections that are made.
I will read everything Laurie King writes about these two characters.