The Secret City. by Hugh Walpole

The Secret City is Walpole's sequel to his earlier book about Russian life, The Dark Forest. John Durward, the English protagonist from that book and a semi-autobiographical stand-in for Walpole, is visiting St. Petersburg (then Petrograd) when he runs in to some old friends from England. Through them he meets Vera and Nina, two young and bourgeois sisters, and Nicolai Markovitch, a downtrodden and ridiculous inventor.
Semyonov, a brooding doctor who is the sisters' uncle and a character from The Dark Forest, returns as a dark, viperous thread weaving through the story. Durward narrates the lives of these bourgeois Russians as they love each other and fight amongst themselves in equal measure. But as they obliviously carry on their cozy, lamp-lit lives, the Russian Revolution breaks out around them. St. Petersburg quickly changes from a comfortable, elegant, and gently mysterious city to a bloody and cold scar across the face of civilization.
As the air fills with the sound of gunfire and the smell of smoke and soot, Durward and his English and Russian friends become a microcosm of the chaos they find themselves engulfed in. Walpole lived some years in Russia during the Revolution, working as a journalist, then at the Russian Red Cross, and later as the Head of British Propaganda in St. Petersburg. His intimate knowledge of both the city and of the turbulent early days of the Revolution give The Secret City a more than convincing air.
It's the first book to have won the prestigious James Tait Black Memorial Prize for fiction, and is considered to be Walpole's most delicate and insightful work.