Midnight Runners Students at the Korean National Police University are Ki-joon, and Hee-yeol. They witness a kidnapping as they return from the club at midnight. However, the missing persons section of the local police station is too busy investigating the kidnapping case of the son of a business magnate. They realize they are now in critical hours following a kidnapping and begin their amateur investigation.
Ki-joon, Hee-yeol and the kidnappers meet up and discover that the gang has an unfertilized egg harvesting ring. There are also many more girls locked up at the hideout. Hee-yeol and Ki-joon try to rescue them, but they are instead beaten up and locked up. They escape their captors and return to their hideout the next day with a cold trail and an empty cache. Their professor informs them that they are not acting officers and advises them to stop investigating the case.
They are unable to wait for the bureaucracy’s resolution to the case and so they re-enter the fray. They go through a lot of physical training to find the kidnappers. With the help of CCTV footage they can track them down to a fertility center. Armed with weapons, they set out to free the girls, but this time, they are better prepared. They manage to take down the boss and all the kidnappers. They are unable to arrest the kidnappers or rescue the kidnapped girls, so they call the police, fearing they could be expelled.
They are however held back one year and sentenced to 500 hours community work. This was due to some members of the disciplinary board believing they had done the right moral thing. The two were satisfied with the result. Mid-credit: Yun-Jung, Yun-Jung’s kidnapper, visits Ki-joon, Hee-yeol and thanks them for saving her.