‘Moon Lovers: Scarlet Heart Ryeo’ episode 12 spoilers, promo: Wang So to marry Hae Soo, King dies, Wang Wook fights So to become the king

"Moon Lovers: Scarlet Heart Ryeo" episode 12 airs Oct. 3, Monday. The show starring Lee Joon-gi (Wang So), Lee Ji-eun (Hae Soo), and Kang Ha-neul (Wang Wook) will feature a highly anticipated kiss and a marriage proposal. Here are the detailed spoilers for the next chapter of the series. Read on to find out what happens next.

[Spoiler alert! This article contains spoilers for "Moon Lovers: Scarlet Heart Ryeo" episode 12. Do not read further if you don't wish to know more about it.]

In the previous episode, Court Lady Oh sacrificed her life for Hae Soo by taking the blame for poisoning the king. While Hae Soo is freed, Oh is taken into custody and later executed.

"If I had known someone would die because of me, I would not have been so greedy to live again. If only this was a dream... if only I could wake up without remembering any of this," Hae Soo is heard saying in the voiceover (as quoted by drama beans) before she faints in Wang So's arms when she hears the gong go for Oh's execution.

Before that, Wang So, who survived the poisoning, tells Wang Wook that it's his mother who is the mastermind behind the sinister plan. Meanwhile, Wang Wook catches his sister Princess Yeonhwa and a court lady red handed.

Moving on to "Moon Lovers: Scarlet Heart Ryeo" episode 12. While not many details are revealed, a promo video teases fight for the throne between Wang Wook and Wang So. Stakes get higher as the two compete with each other to become the king.

The trailer for "Scarlet Heart: Ryeo" opens with someone telling to get rid of Hae Soo. Orders are that she should be sent to a place where she can't ever be in contact with the princes.

Meanwhile, Wang So and Hae Soo come closer. He pays a visit to Hae Soo where he hugs her and tells her that he missed her. He confesses his feelings for her and asks her to marry him.

The news reaches Wang Wook and it seems it won't go down well with him. Fans can expect to see the two princes fight each other in episode 12. The trailer for "Moon Lovers: Scarlet Heart Ryeo" shows a tense moment between the two as they hold each other by their collars.

"If I say I'm getting married, I'll get married," Wang So tells Wang Wook.

Meanwhile, the King's life is in danger. He gets a warning to not attend the meeting. Next shot shows the king die after being attacked in the meeting. The last scene shows, Wang So and Wang Wook come face to face in an amphitheatre where they combat to become the king.

"Moon Lovers: Scarlet Heart Ryeo" episode 12 airs Oct. 3 at 10:00 pm on SBS. Stay tuned for more spoilers and updates.