A good mystery but it dragged on and I lost interest. I thought the writing was good, but this book wasn't for me.
I received an ARC copy of this book from netgalley.

a good historical with an interesting plot. Overall solid writing.

3.5 stars
Even her family’s ball cannot distract Lady Cassandra Eastham from the very serious business of her life secretly translating highly confidential documents for agencies of the British and Portuguese governments. When an important message arrives on the night of the ball, Cassandra, eager to read it, escapes to the seclusion of a dark corner. There she is interrupted by Weston Barrington, the Earl of Armadale and a hero in the Peninsula War.
Although Lord Barrington appears eager to resume the life of an English gentleman, Cassandra instinctively distrusts him and refuses to be seduced by his dashing looks. Lord Armadale West to his friends believes there is a spy in the Eastman household, but is drawn to Lady Cassandra despite his determination to remain a bachelor. When a brutally injured young woman arrives at Eastham House and dies in the marble foyer, the incident unites him and Cassandra in a dangerous partnership.
I really enjoyed the book, mysteries as well as romance. The plot was well paced & kept me reading, I also wanted the mystery solved. The characters had depth & on the whole were likeable. There were of course misunderstandings & intrigue. I’d certainly recommend the book & will read more from the author

This novel was an enjoyable read. It combines action with mystery and secrets. Many things are discovered in this story about two people brought together for the work they do for the crown.
Lady Cassandra Eastham translates messages for the crown, but they believe it is her father. Cassandra's father has difficulties with his memories, so she takes it upon herself to keep up with the correspondence and keep her father's mental state a secret. While at a ball, she receives a letter, but is interrupted by Weston Barrington, the Earl of Armadale. He is a war hero and also speaks Portuguese, like Cassandra. He believes there is a spy in the Eastham home and his mission is to discover who it is.
Cassandra distrusts West, however, West is very interested in Cassandra, who is more than she seems. She is a determined woman West is attracted to Cassandra, but does not want to be tied down and he has his own secrets too.
When a woman looking like Cassandra comes to the Eastham home and dies, both West and Cassandra have to work together to solve the mystery of why she was murdered, why she came to the Eastham home, and why she looks so much like Cassandra. Each piece of information they gather leads them closer to the truth. However, they need to overcome several obstacles in their way from those who want to keep their secrets as well as those that seek to earn a fortune. West and Cassandra also battle their growing attraction for each other. West will do whatever is necessary to protect Cassandra, even if it means staying at her home and taking her with him on "outings". Both realize they love each other, but is it enough? Will West and Cassandra discover the murderer? How will they handle the secrets that are uncovered?