"Reign" returns this week with episode 17, titled "Liege Lord." The episode reveals the secret clause in Mary and Francis's marriage contract. This revelation is set to lay the base for Mary to rise as the Queen of Scotland in the true sense.

In the episode, Mary, to her shock, finds out that Scotland will belong to France if she dies without an heir. The synopsis of the episode reveals that this secret clause was inserted in her marriage contract by Mary's mother and Queen Catherine. Mary feels that Francis's family has once again betrayed her.

In the Insider clip, Francis can be seen telling Mary that it is not only his family that has betrayed her, suggesting that Marie de Guise has played an equal part.

Francis fears that if Mary is not announced as the successor to England's throne, King Henry might kill her to "cut his losses." Once Mary is dead, King Henry will take over Scotland and it his staging ground to invade England.

Brad Silberling, co-executive producer of "Reign," has said that this episode provides a real glimpse of Mary's rise to power and harnessing of that power.

"We will now see Mary have to make a very, very specific and big choice in her leadership of choosing her country and its future or France in a specific way that we've never seen before," Silberling said in the Insider clip.

[Youtube/The CW Television Network]

According to Laurie MaCarthy, co-executive producer of "Reign," the rise of Mary as Queen of Scotland will cause the fall of Mary's innocence. Mary's rise as the Queen of Scots will cost lives, as well, as Mary and France will try to turn Scotland against Marie de Guise.

Official Synopsis of "Reign" Episode 17 "Liege Lord": "When Mary learns of a secret clause in her marriage contract that her mother, Marie de Guise and Queen Catherine orchestrated, Mary and Francis embark on a dangerous plan to turn Scotland against her mother -- and Mary gets her first taste of power as the Queen of Scots."

Allan Kroeker has directed "Liege Lord," written by Doris Egan.

[Youtube/The CW Television Network]