This was an intense legal/political thriller that I raced through and thoroughly enjoyed.

The book is written as a dual narrative. Anna is a lawyer and is asked to take on another unpaid case after speaking to Rosa. Her sister Natalia was recently found dead after drowning in the Thames, but Rosa believes it was not accidental. Anna is immediately interested as her own sister disappeared suspiciously over 12 years ago in Tokyo. She can emphasise with Rosa and is desperate to uncover the truth.
The other narrator is Kat, who has recently been promoted as special advisor to the home secretary. Kat starts to discover a series of cover-ups and finds a worrying letter about a girl, Natalia, who recently drowned in the Thames. Could her new boss be involved?
I loved how the two main stories slowly interlinked. The two main characters were really well written and easy to identify with.
I found the dark storyline compelling to read. It was packed with action, suspense, and twists. 
I haven't read Anna Sharpe's/Mazzola's historical fiction yet (although I do have them all on my tbr) but I hope this is the first in a series as I would love to read more books with Anna and Kat in. 
If you like a fast-paced thriller, I would recommend this!