David Dickinson 
Death on the Nevskii Prospekt [EPUB ebook] 

1904: Powerscourt comes out of retirement for one last time, heading for Russia in one of the strangest cases of his career.A British diplomat has been discovered, his throat cut, on one of the bridges spanning the Nevskii Prospekt in St Petersburg. It transpires the diplomat knew a secret — and that secret killed him. As Powerscourt strides through the halls of the Winter Palace and falls foul of the Okhrana — the Russian secret police — he has to attend other matters. Russia is on the verge of revolution and he must escape — before time runs out on him.