The National Intelligence Service lost another team during a field mission. They learned that "Michael Lee" is their main suspect for the crime.
The team leader Dong Kwan-soo will head the operation to capture their suspect. He needs a new group to do all the plans on the field. The NIS director endorsed the agent Baek Chan Mi whom all other detectives dislike to work with. She is brave, smart, and fearless when it comes to any mission she gets into.
The last mission she went as an undercover agent is a prisoner at the women's correction. She needs to get the chip, which was taken by a Russian inmate for safekeeping. She lives and acts like any other prisoner and goes into the isolation room to get the code. After she knew the code, she went ahead to meet the Russian inmate and brawled with her until she gave in. She got the chip and sentenced the Russian for an additional three years.
By the time she reached the chief office to report, he had given her the position transfer, as advised by the NIS. She's eager to know the team since almost three years ago from her last field mission. She was the team leader of that mission to capture "Michael" but her stubbornness to follow orders, one field officer died that day.
The second member is Hwang Mi-soon, who pretends to be an insurance agent for her family's protection. She reports to the station and works in the audit department. The last field mission she joined was with Baek Chan Mi, where they lost a police officer in their pursuit to capture "Michael." She declined to accept the new assignment, but team leader Dong gives her the statement account of her loan balance to pay if she won't join.
The third member of the field agent is young and smart Im Ye-Eun. She works in the IT department and helps any police agency in the filed for technical concerns and liaise with them through their mission. She has a 3-year-old daughter whom she struggles to support. She lives within means and stays at the police shelter to save what she earns for her daughter. Her husband is an undercover agent who died on a mission the day she gave birth to their child.
The three ladies will head as the field agents in the search for "Michael" with teal leader Dong's guidance.
Baek Chan Mi requested Im Ye-Eun to meet her at the gym to practice her skills in fighting. As they started to do basic martial arts, Chan Mi slams Im Ye-Eun many times, which lost her strength. Chan Mi advised her to work on it before she dies and is lost on the battlefield.
Im Ye-Eun did not know about her late husband's mission. It was a secret mission led by Chan Mi. She tried to call him, but it was too late already. Chan Mi and Mi Soon lost a great friend and an agent that day. Now, Chan Mi is back and she went to visit Min Seok in the charnel house to let him know that she will do everything to catch "Michael" and revenge for his death.
