Bastions of Blood (Kremlins #2)
L.K. Hill, K.L. Conger

On the heels of a triumphant victory, Tsar Ivan falls ill, followed by his beloved wife. The Tsarina's condition worsens, and Inga sees glimpses of the sadistic creature Ivan was before he married. As Ivan’s madness grows, he lashes out, and all of Russia feels the sting.
As Inga fears the future, Taras looks to the past, searching for the elusive answers to his mother’s death. As mystery piles upon mystery, and everyone refuses to talk, Taras begins to wonder if he’ll ever truly understand the event that has plagued him since childhood.
The Kremlin darkens and the countryside fills with blood. Inga and Taras cling to one another for survival. If no one reins Ivan in, they may end up losing more than their lives.