After overcoming plenty of difficult, valiant and beautiful Yoon Soo Seon succeeded in passing Police Civil Service Examination and became a criminal policewoman in Gangnam Police Department. She, Eun Dae Gu who has a feud, Park Tae Ro who is an aristocratic childe and Ji Kook who’s pawky and unambitious are assigned to the No.3 strong team led by the team leader, Seo Pun Suk. The brave Leader Xu is an excellent criminal policeman who’s made great achievements, but the four rookies do confuse him. The four always make trouble and sometimes destroy the action of other departments. Nevertheless, Leader Xu has determined to teach them in three months. With the arduous training and continuous cases, what Dae Gu and Soo Seon are digging themselves is about to be clear....