Retired With Prejudice by Olivia Stowe

In the second of the Charlotte Diamond mysteries, FBI senior investigator Charlotte has retired to Maryland's eastern shore of the Chesapeake bay only to find high-level international intrigue has sought her out when the abandoned sailboat of spy master Win Engleton washes up against her dock. Charlotte struggles with having to choose between focusing on her new-found significant other, former movie star Brenda Boynton, or a complex espionage mystery of who did what to who and why that reopens ever deeper mysteries again and again like a Matryoshka Russian nesting doll.