Season 1
After his promotion to inspector, Jang Jae Gyeong is abducted for three days. Just moments before, he received an SOS text message from a former friend referencing the name "Doctor". The new and potent "Lemon Mulberry" drug is injected into his system and one pill is left in his coat. Suffering withdrawal symptoms and only flashes of what happened to him, he needs to find out the connection between him and this mysterious "Doctor".
01. Episode 1
After meeting a friend from 20 years ago, Jae Gyeong gets abducted and becomes addicted to an unknown drug.
02. Episode 2
Jae Gyeong reunites with his friends from 20 years ago and finds them suspiciously linked to Jun Seo's death.
03. Episode 3
Jun Seo's body undergoes an autopsy, while Jae Gyeong and Yoon Jin dig deeper into Myung Guk's identity.
04. Episode 4
Jae Gyeong finds a lead in solving Jun Seo's death, and Yoon Jin discovers something shocking about Ji Yeon.
05. Episode 5
Someone tries to stop Jae Gyeong from investigating Jun Seo's death, but it doesn't stop him.
06. Episode 6
Jae Gyeong connects Lemon Mulberry to Jun Seo's death. With a lead, he goes undercover to meet the dealer.
07. Episode 7
Yoon Jin faces an unexpected crisis, and Jae Gyeong gets a lead from a dashcam video that makes him freeze.
08. Episode 8
Jae Gyeong connects incidents on the day of Jun Seo's death that reward him with a lead in the mill murder.
09. Episode 9
Jae Gyeong connects the murder of the mill owner to Jun Seo's death while fighting withdrawal symptoms.
10. Episode 10
Jae Gyeong chases down the person who drugged him, leading him to CEO Yoon and closer to solving the case.
11. Episode 11
Jae Gyeong chases Yoon Ho with Si Jung's intel, and Yoon Ho makes his last attempt to escape and survive.
12. Episode 12
Suspicion and distrust form over Yoon Ho, while Sang Eui exposes the truth to Jae Gyeong and Yoon Jin.
13. Episode 13
Tae Jin retaliates against Jong Soo's attack, while Jae Gyeong sets up an operation to arrest Jin Wook.
14. Episode 14
The connection between friends driven by greed comes to face a tragic end to learn the meaning of friendship.