Mary Queen of Scots (Adelaide Kane) is set to prepare for the invasion Spain in "Reign" season 3 episode 8, according to recent spoilers.

"Reign" season 3 episode 8 is entitled "Our Undoing." According to MNR Daily, the next episode of "Reign" season 3 will see Mary and Catherine (Megan Follows) opt to satisfy the sexual desires of the Prince of Asturias (Mark Ghanime).

In the previous episode, Mary tried to form a union with Spain by marrying Don Carlos. It was also revealed that when she was to secure her engagement with Don Carlos, she discovered that the prince had a horrible secret. Mary learned that the mentally unstable prince had a desire for masochistic activities.

Archives revealed that Carlos' psychological deviation began when he was young. He was said to cause physical harm to anyone surrounding him. Carlos reportedly tortured girls and servants when he was nine years old. In addition, he caused injury to the horses in his father's stable, which left their servants with no choice but to kill them to end their suffering.

Mary was initially against Carlos' nature; however, Catherine persuaded her to deal with the prince's mental state. However, the recent "Reign" promo trailer saw people advise Mary to escape, since Spain is coming for her and her fate with them will not end up well.

Meanwhile, the series is set to have eight seasons in total. Also, it will lose its Friday timeslot to "The Originals" and "Vampire Diaries," according to CarterMatt.

"Reign" season 3 episode 8, "Our Undoing," airs on Jan. 11, 2016 on The CW.