I received this book in a Goodreads giveaway.

I haven't read the previous book by Robertson that introduced the characters in "Circle of Shadows" but that isn't an impediment to enjoying the story. It did take me a while to get into the book but once I was a few chapters in I couldn't wait to finish it. I thought the start was a little slow, and some of the transitions were a little clumsy but overall I thoroughly enjoyed the book. I plan to read the earlier book in the series and look forward to new stories. ( )

Not nearly as good as the last installment in the series. Still complex and well-written, and perfect for a quick summer read, but this one didn't have as much backstory or develop the characters as well as the third volume did. ( )

http://www.girllostinabook.com/2014/08/review-circle-of-shadows-by-imogen.html ( )

In Imogen Robertson’s Circle of Shadows, Harriet Westerman and her companions travel from eighteenth century England to the Duchy of Malberg on hearing that her sister’s new husband, Daniel Clode, has been arrested for murder of Lady Martesen. They must work quickly; the Duke is about to get married and does not want this distraction in his court. Both Harriet’s understanding of human nature and the scientific knowledge of her friend, anatomist Gabriel Crowther are required to unravel the tangled intersections of alchemy and science, spycraft and secret societies.The complications of the human heart and the convoluted politics of German principalities must be unknotted if Daniel is to go free.
I enjoyed the independent character of Harriet Westerman and found the descriptions of life in the court of Malberg fascinating. The plot was rather complicated at times and while the resolution might seem contrived in another era, it worked here. I’d be interested in reading about Harriet’s next adventure. ( )

This mystery title has it all. Featuring the always fascinating locked room mystery, Circle of Shadows is number four in author Robertson's series of historical mysteries. Although this title was new to me, I found this a compelling read which will definitely make me seek out the author's earlier books.

Englishman Daniel Clode had been traveling in Germany when he unwittingly awakes in a locked room next to a dead body and finds himself accused of murder. Daniel's sister-in-law, Rachel has been involved in unraveling other investigations and she travels to Germany with her friend, anatomist Gabriel Crowther to investigate the mystery. The book features wonderful characterization of both primary and secondary characters. Historical details and a description of 18th century forensics will intrigue the reader. The atmosphere is quite Gothic and satisfying for readers who like a challenging puzzle combined with historical accuracy. Although the story builds upon details revealed in earlier books in the series, Circle of Shadows can be read as a standalone. It was thoroughly engrossing and hard to put down. Highly recommended. ( )