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Checked October 11, 2026
Available in 2 other countries 2 with streaming
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Availability history in United States
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Overview
20 years ago Moo-Yeom’s father was a suspect in the "Gap Dong” serial murder case. Because of the detectives’ oppressive investigation, Moo-Yeom’s father killed himself. Now, Moo-Yeom is a detective and works to capture the killer Gap Dong. The statue of limitations has expired for the serial murder case and Moo-Yeom resigns to the belief that Gap Dong is dead. New clues though for Gap Dong appears in front of Moo-Yeom and he sets out to catch him once and for all.
Cast
Jung In-giCha Do-hyeok
Jo Min-junLee Hyung-nyeon
Yoon Sang-hyunHa Moo Yum
Kim Min-joungMaria Oh
Sung Dong-ilYang Cheol-gon
Lee JoonRyu Tae-oh
Kim Ji-wonMa Ji-wool
Kang Nam-gilHan Sang-hoon
Min Sung-wookNam Ki Ri
Yoon Kyun-sangYoungest detective
Choo Soo-hyunOh Young-ae
Yoon Chan-youngyoung Ryu Tae-oh
Hyun Wooyoung Cha Do-hyeok
Jeong Jae MinHa Moo Yum [Young]
Ha JunNah Do-Hyung
Seasons and episodes
1 season20 episodes
Season 1
A police detective strives to clear his deceased father's name by catching the real serial killer who terrorized the country 20 years ago.
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Episode 1
Mu-yeom who became a detective for his father, receives news like a nightmare.
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Episode 2
Hearing something suspicious about the body of a murder case, Mu-yeom rushes to the crime scene.
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Episode 3
It's reported that the first case is the act of Gabdong and there will be a second case of murder.
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Episode 4
Mu-yeom is arrested as a criminal, and Yang suggests to compare the DNA of Gabdong and Mu-yeom.
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Episode 5
Chief Yang meets Maria and thinks of a girl he met at the scene for a case from a while ago.
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Episode 6
Mu-yeom suspects Tae-oh as Gabdong. Tae-oh lets out the story of his dead father to Maria.
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Episode 7
The civilians blast anger and attack the police for failing at preventing the fourth case.
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Episode 8
Mu-yeom kidnaps Ji-ul and tracks down Tae-oh, with the predicted date for a fifth case approaching.
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Episode 9
After finding a corpse, Mu-yeom runs at Tae-oh, and Maria witnesses something shocking.
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Episode 10
A phone call rings from the real Gabdong. Mu-yeom finally gets to know the true identity of Gabdong.
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Episode 11
Gabdong is finally caught. Mu-yeom starts the interrogation and goes to get his shut mouth talking.
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Episode 12
The plane the murder happened at, which Tae-oh was in, makes a flyback.
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Episode 13
Tae-oh confesses his crimes, and Maria is shocked after finding out that Gabdong's probably dead.
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Episode 14
After finishing the montage, Maria turns the young Gabdong montage into Gabdong of the present.
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Episode 15
Mu-yeom and Tae-oh, neither one of them slows down and races to the end of the cliff.
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Episode 16
Mu-yeom interrogates to prove Do-hyeok as Gabdong. He gets closer to the secret of the Murder case.
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Episode 17
While searching Do-hyeok's house, Mu-yeom finds a suspicious picture frame of the Eiffel Tower.
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Episode 18
Tae-oh starts a deal between Do-hyeok and Maria. Mu-yeom notices and makes the two Gabdong gather.
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Episode 19
A gunshot rings at the pool Mu-yeom and Do-hyeok are at, and someone falls bleeding.
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Episode 20
The trial of the two Gabdong finishes, with hard choices to make, the two fall into a great dilemma.
If you like Gap Dong
+8 
+2 
+11 
+8 
+18 
+6 
+7 Ratings and comments
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