Yoo Oh Sung plays a North Korean spy, who will be in confrontation with the main character Seon Woo. Bae Jong Ok plays Seon Woo’s mother. Bae Jong Ok plays Hye Rim – a perfect mom inside and out. She pays a lot of attention to her children’s education. She’s also a perfect housewife who supports her husband very well. But in fact, she’s former North Korean informant. Out of the blue, she’s assigned the mission of recruiting her son, who works for National Intelligence Service (NIS), into espionage activity. In order to protect her son, she can do anything, even gamble her life. In the drama, Kim Jae Joong plays a genius analyst on North Korea information, who works for NIS and has genius brain. He has extraordinary analytically skills and could make quick and cool-headed decisions.