"Reign" returned this week with a focus on Bash, who may now be the future king of France.

In "For King and Country," Mary (Adelaide Kane) and Bash (Torrance Coombs) are fleeing the castle, but are soon captured and brought back.

Back at the castle, the king realizes that Catherine (Megan Follows) was partially behind Mary's disappearance, and forces her to explain why she broke up Mary and Francis' engagement. She doesn't tell him the truth about the prediction, but says there would be devastation if the two get married.

Once Mary and Bash return to the castle, Francis (Tony Regbo) tells Mary that he loves her, while the king (Alan van Sprang) tells Mary that she must wed Francis or he will have Bash executed. The king even threatens to execute his wife.

Mary is then able to maneuver a scheme to get the king to legitimize Bash, meaning the two will get married instead.

Mary also writes to her mother, who will join the show later on in the season.

Meanwhile, in the dungeon, Nostradamus (Rossif Sutherland) is with Clarissa (Katie Boland), the girl who has a bag over her head due to a severe disfigurement. Suddenly, Clarissa stabs Nostradamus, leaving fans questioning the fate of the dark soothsayer.

On the next episode, "Sacrifice," Queen Catherine will be suspected of orchestrating a plan to kill Bash when the plan goes awry.

Showrunner Laurie McCarthy told E! Online that Mary and Bash's relationship will evolve, even though Mary's heart will still be with Francis.

"I think you'll see Mary and Bash investing in a relationship with each other, and there's good raw material there for something to grow," McCarthy said.

Mary will develop feelings for Bash, which will create a very complicated love triangle.

"They will start to have real feelings together, because she's going to believe that that's her fate, and she's a practical girl," McCarthy explained. "And I think again, there are genuine feelings there as well, I think she's truly torn. But I will say I think she has a deeper affection, a longer-lasting affection, for Francis.

"I've always looked at the show as, because other girls will be married too, at some point, and when you're married in the sixteenth century, it can mean a lot of different things," she continued. "What it usually means is your marriage is forever, but because your marriage is forever, there are plenty of different versions of a marriage, and when you look back at characters, you don't know if they loved each other deeply, but they grew estranged because of their obligations, or if they loved each other deeply and were able to stay together, or they never loved each other at all but lived their true relationship life with someone else. But I believe that Mary and Francis deeply love one another."

Francis will explore his newfound freedom and even travel a bit. However, he may not be well suited for a life of leisure.

Also, Francis' relationship with Bash will become increasingly antagonistic, as Bash will become a threat to Francis in every way.

"Bash becomes a threat to him basically in terms of Francis's family, meaning his mother, his brothers, technically his little sisters, but we never see them. But kind of like Mary and Francis, they genuinely love each other. They have a real kinship, and I think they are always going to be looking, at some point, once the clouds of their rage clear, to find ways to be brothers again."

McCarthy also hinted that Catherine will try to get out of a trial for heresy by drumming up her defense from other inhabitants of the castle.

In other "Reign" news, TVLine reports that Kathryn Prescott has been cast as Penelope, a kitchen servant who finds a bean in a slice of cake and becomes queen for a day. Penelope is described as shy and pleasant with a hidden sexy, manipulative side. Prescott played Emily Fitch on the British series "Skins."

Watch the promo for "Sacrifice" below, which airs Thursday, Jan. 30 at 9 p.m. EST on The CW.