The Royal Assassin — Kate Parker

From the author of The Vanishing Thief and The Counterfeit Lady comes an all-new Victorian mystery featuring antiquarian bookseller Georgia Fenchurch, who doubles as a private investigator for the secret Archivist Society…

When the Duke of Blackford enters her bookstore, Georgia knows the Archivist Society is in need of her services. The Tsar of Russia and his family are visiting Queen Victoria on the auspices of the engagement of the Russian princess Kira to the son of the Queen's cousin. When Kira's bodyguard is found dead on a train returning from Scotland, the Queen calls on Blackford to discreetly protect the princess and prevent an international incident.

The Russian royalty refuses help in finding the murderer, suspecting anarchists and demanding every extremist in London be hanged. But that is far from the English way. To get the job done, Georgia must go undercover as Kira's English secretary. She soon discovers that anarchy isn't the only motive in the case -- and that someone is determined to turn royal wedding bells into a funeral dirge.