Judith Pella & Michael Phillips 
Travail and Triumph (The Russians Book #3) 

From Siberia to St. Petersburg, tsarist Russia continues to crumble. The noble house of Fedorcenko, however, has much to rejoice in: the marriage of Princess Katrina, the anticipation of a new baby, and the return of Prince Sergei. But even as they celebrate, rebel forces are at work to overthrow the tsar–and the house of Fedorcenko as well.