Catherine travels to Russia and becomes the Empress by marrying the Emperor of Russia, Peter; Catherine soon realizes Peter is a selfish brat and feels hopeless until her servant, Marial, presents her with an alternative path -- to overthrow Peter.
Catherine takes her first steps toward a coup; she attempts to seduce and recruit palace intellectual Count Orlo; it's a disaster; however, after seeing Peter's brutal treatment of local nobles, the count decides to join Catherine's coup.
Catherine, Orlo and Marial continue their coup planning; they try to recruit an unhappy military general, Velementov, for their cause; Peter, noting Catherine's unhappiness, gifts her with a sterile lover, Leo.
Catherine tries to manage her reputation at court and her relationship with Leo, both of which distract her from the coup; the influential Patriarch of the church dies, and a new one must be chosen.
As the war with Sweden rages, Catherine and Aunt Elizabeth visit the Russian front; Grigor poisons Peter; Velementov, Orlo, and Marial try to influence Catherine's steps toward takeover, as Peter's life hangs in the balance.
Peter has a new lease on life after his near-death experience; he is open to Catherine's progressive ideas of introducing art and science to court and wants to focus on an heir; Orlo tries to figure out who poisoned Peter and faces demons of his own.
Catherine feels optimistic about peaceful coexistence with Peter and their increasing chemistry; when smallpox breaks out in the servant's quarters, Peter reverts to his old ways; Leo and Catherine's relationship suffers, and Georgina misses Peter.
Catherine's political abilities are tested when she's given an opportunity to travel abroad with Peter and Velementov to discuss ending the war with Swedish king; Velementov sees the potential of her leadership and decides to support the coup.
Tensions mount as Catherine, Orlo, Velementov, Leo, and Marial try to get regional counts on board with the coup; when a body is discovered, Peter decides to torture everyone to find the murderous traitors; Catherine realizes she is pregnant.
Catherine decides to move forward with the coup on her birthday; Peter holds Leo hostage as collateral; Marial betrays Catherine to Peter; Catherine realizes that the only chance for a greater Russia is to fight, without Leo; the battle begins.