Ki-joon and Hee-yeol are best friends and students at the Korean National Police University. One night while out drinking in Gangnam, they witness the kidnapping of a young girl and consequently report it to the Gangnam police station. However, the station’s Missing Persons Unit prioritizes a high-profile kidnapping of a business mogul’s grandson over the case. Knowing they are in the critical hours after a kidnapping, the duo take matters into their own hands.
Through their amateur investigation, Ki-joon and Hee-yeol catch up with the kidnappers, who are running an unfertilized egg harvesting ring, and learn that many more girls are locked up in their hideout. Ki-joon and Hee-yeol try to save them, but are beaten and locked up. After escaping their captors, the duo later return to an empty hideout and a cold trail. As they are only students, their professor Yang Sung-il warns them against pursuing the case or risk facing expulsion.
Unable to wait, they once again embark on their own investigation. With the help of CCTV footage, they track the van to a fertility clinic. They undergo heavy physical training and “borrow” armor equipment from the University. Ki-joon and Hee-yeol go to the fertility clinic, where they subdue all the enforcers, including their boss Yang-choon. They call the police to arrest the kidnappers despite knowing they will get expelled for their actions.
Due to some of the disciplinary committee members in university believing that they had done the right thing morally, Ki-joon and Hee-yeol are instead held back a year in their studies and sentenced to 500 hours of community service, leaving the two satisfied with the outcome. While completing their community service, Yun-Jung visits Ki-joon and Hee-yeol and thanks them for rescuing her.
