Seolhyun will portray the character of a smart and progressive woman named Han Hee Jae. She becomes dispirited due to the large cases of corruption in the country. Then, she encounters Seo Hwi (played by Yang Se Jong) and Nam Sun Ho (played by Woo Do Hwan). The story will focus on the trio, plus Lee Bang Won (portrayed by Jang Hyuk).

In the teaser, the AOA member picks up a brush and begins scribing as her voice from the narration says, "I will have it, strength. I will have that strength so that I don't lose anyone." At the end of the teaser, she looks straight up with an intense stare.

Previously, another trailer clip was released, which depicts a brutal fight scene and with Nam Sun Ho gradually emerging from a building in flames. Seo Hwi then crafts his weapon and says, "I will become strong. There's someone I must protect."

Flashbacks of his poor and difficult life as a child also come about. With a dark aura, Nam Sun Ho says, "Goryeo will fall. When that happens, I will stand in the center. I will take it. Even if that means I lose you." The clip also hints a complicated bond between him and Han Hee Jae, with the latter slapping the former on his face before saying, "It's not right. That's why I'm angry. I'm going to become stronger. So I don't lose anyone."

The teaser ends with Lee Bang Won and Lee Saek (portrayed by Lee Seung Chul). Lee Bang Won puts down his sword and rises in front of Lee Saek. The latter told him, "I never told you to stand," to which Lee Bang Won responds with, "You never told me not to." Lee Bang Won then casts a glance to the throne.

Meanwhile, the production team earlier provided a little detail about the story.

"A fierce story with figures of firm faith in the turbulent times of the Joseon Dynasty will be unveiled. Woo Do Hwan, who will be rediscovered as an [true] actor beyond his status as a trendy [star], will showcase a powerful transformation. You will be able to check out Woo Do Hwan's presence as he portrays Nam Sun Ho with his own style," they hinted.

My Country will air its pilot episode on October 4th at 10:50 in the evening KST.