The midseason premiere of "Reign" season 3 saw Mary, Elizabeth and Catherine struggling against a Protestant extremist and a serial killer.

Titled "Succession," the episode revealed much about the mysterious character of John Knox, the Protestant zealot who was ruining Mary's homecoming plans through spreading lies about her in her own homeland. Not taking his threats seriously, Mary resorted to finding a Protestant husband who could be her ally in strengthening her Protestant ties.

Just when Gideon was about to convince Mary to accept his offer of a political marriage, John Knox went all the way to ruin Mary by storming the castle gates and setting her effigy on fire. Realizing that a husband would not be enough to rebuild her image, she headed to the Vatican to raise a Catholic army to take her country back.

Gideon reminded Mary that her move would only annihilate her alliance with England, but Mary was so determined to be queen she would not let anyone--not even Gideon--stand in her way.

Meanwhile, Elizabeth compelled Lola to reveal Mary's secrets, but Lola understood the meaning of loyalty so she did not. She found out that it was Lord William who poisoned Elizabeth and made her lose her baby. The moment Elizabeth heard the news, she held on to her power and took down William for his treachery. She realized that Lola and Mary were not really her enemies, but instead those who pretended to be her allies.

While the turn of events brought Mary and Elizabeth into highly empowering positions, Catherine saw herself in serious danger when she learned about a serial killer who had entered the castle gates just before her son's coronation.

The most shocking part of the episode was when Catherine discovered that her lover Christophe was actually the one behind the series of murders. Fans of the series have always known Catherine for being shrewd and scheming, but the previous episode proved that she must have found her match in Christophe. Her new boy toy will be her new adversary, as she would let him kill people just so he would not reveal all her backhanded deals and give up her being regent.

"Reign" season 3 returned on April 25 on The CW.