Death on the Nevskii Prospekt (Lord Francis Powerscourt Murder Mysteries)

Powerscourt, coaxed out of retirement one last time, heads for St Petersburg where a British diplomat has been discovered, his throat cut, on a bridge spanning Nevsky Prospekt. It would seem the man knew a secret — and it proved fatal. As Powerscourt paces the Winter Palace and ponders the mystery, other matters press in on him. With Russia edging towards revolution, he must make his escape — before time runs out on him too.