Perky and energetic Yoo Ryung (Geun Young Moon), a rookie police investigator with a special gift of wide visual spatial recognition, which makes her able to notice crime clues others miss from far away, became a policewoman in order to find her missing twin sister, who is autistic. She believes her sister might be either a kidnap or murder victim of a current mysterious serial killer on the loose, who has been targeting victims on Seoul's high speed subway lines, and who has been nicknamed the Subway Ghost, even though he's very much human. He's got the entire city terrorized, leaving a trail of victims behind of all ages and sexes. No one knows when he will strike next. It is imperative that he be caught, but too often the police entailed to the case have bungled it repeatedly. (Keystone Kops, move over!).

On orders of the upper crust in the police department, including Captain Kim Hyung Ja (Song Ok Suk, who played the middle aged Ahjumma cellist in Beethoven Virus), Yoo Ryung ends up becoming professional partners with handsome police officer Go Ji Suk (Kim Sun Ho), and they both become determined to catch the Subway Ghost together.

While Yoo Ryung has her tragedy of a missing sister to be concerned about, Hyung Ja has his own personal tribulations going in his private life too, taking care of his mother Han Ae Sim who has dementia (played touchingly well by wonderful actress Nam Ki Ae from Mother). In some very bittersweet scenes we see her mistaking her son for her deceased husband, and Ji Suk just plays along, to give her some rare pleasure. What a good boy!

The more Yoo Ryung works with Ji Suk the closer they become as partners and pals. They handle some other cases together too beside the serial killer case, and learn to rely on each other's talents more and more. Will that develop into a romantic relationship though? He still has some left over feelings for his ex-girlfriend, policewoman Ha Ma Ri (Eugene Jung from Romance Is A Bonus Book), and sometimes Yoo Ryung is distracted by Metro Police Officer Kim Woo Hyuk (Ki Do Hoon), who admires her talents as a dedicated policewoman.

However, as time goes by Yoo Ryung finds herself depending more and more on Ji Suk and not Woo Hyuk (hey, that rhymes! lol). Sometimes her personal feelings confuse her, but never once does she give up on her ultimate goals of finding out what happened to her disabled twin sister or catching the evil serial killer. Will she be victorious in the end, or become a victim of the serial killer herself?

Love you, Korea's Little Sister!
Stay well! 

Although the drama tended to drag a bit in the middle, I really loved the energy of the beginning and end parts of this drama, and I loved to see Geun given a chance to play some comedy scenes, as well as typical melodramatic ones. If you love these actors definitely put Catch The Ghost on your K-drama Watch List. It's very entertaining! Enjoy.