Tae Joo, a detective with principles, is asked for a favour by his ex-girlfriend, who is a prosecutor. While pursuing a man suspected to be a serial killer, he loses consciousness after getting hit by a car. When he wakes up, he finds himself in the year 1988. (Source: Viu)

Despite being confused of his current situation, Tae Joo works hard with the detectives in 1988 to solve a murder case. Upon looking at the case, he is certain that it is a serial murder. He has a hard time accepting the way that the 1988 detectives work and gets into an argument with Dong Cheol. Tae Joo is determined to find his way back to 2018. In order to do so, he makes a dangerous decision. (Source: Viu)

Tae Joo is confused as he can’t tell if he is dreaming or not. He wonders why he’s been sent to where he is now, but he can’t figure out why. Meanwhile, the detectives pursue the suspect of a pickpocketing case. By sticking to his principles, Tae Joo puts his colleague at risk. (Source: Viu)

A dead body turns up in a field of reeds. They find the suspect of the murder, but Tae Joo doesn’t think that their suspect is the killer. Dong Cheol disagrees and is certain that the person they caught is the murderer. Meanwhile, Tae Joo begins to remember parts of his past that he had forgotten about. (Source: Viu)

A woman reports a break-in, but as it turns out, nothing was stolen from her. Meanwhile, the gang at Seobu Police Station finds out about a similar case. They find out the one thing the two victims had in common and track down the victim. (Source: Viu)

Tae Joo meets his father, who passed away when he was young. Before he can recall the warm memories with his father, another murder occurs. In the midst of solving this crime, he is reminded of how important a father is in a child’s life. The closer they get to solving the case, the clearer his memories become. The missing puzzles of his lost memories come together. (Source: Viu)

Fugitives are on the run and have taken a family hostage in their home. Officers of the Seobu Police Department are the first to arrive including Han Tae Joo who makes it his mission to keep everyone alive. As the hostage situation worsens, the Seobu Police resort to desperate measures endangering their own lives to rescue the innocent. (Source: Viu)

A woman is found murdered in a motel room. Han Choong Ho, who was first released by the Seobu Police Department, is the first suspect in the case. But for some reason, Han Tae Joo is the only one who doubts the possibility Han Choong Ho is the one they should be after. Han Tae Joe’s reoccurring flashbacks of his childhood memories lead him to a place that might be where his father is but only confuses him more of the reality he now lives. (Source: Viu)

Han Tae Joo witnesses his father being shot at a reoccurring place in his memory and ends up rescuing his younger self hiding in the tunnel. Despite the warnings about the Seongho Gang, Han Tae Joo charges after Oh Jung Man, the boss and the man he suspects who had called the hit on his father and Go Yeong Suk, and brings him in for questioning. However, there is more to know for Han Tae Joo, as Oh Jung Man walks out smiling freely with a very influential man of Insung behind him. (Source: Viu)

Han Tae Joo’s pursuit of his father’s killer and the intangible Kim Min Seok gets more distant as the detectives of Insung are baffled once again when another murder case arises. Nothing seems to be certain. However, the body of the dead woman leads Han Tae Joo and the team to her house where they find traces of Kim Min Seok’s existence. Can all of these murders be connected, but how? (Source: Viu)

With the prime suspect ending up dead during questioning, the detectives of Seobu are thrown into confusion, having doubts and suspicions of one another. However, they press on unsupported and get closer to catching the real culprit. As things start to turn for the worst, Han Tae Joo receives a phone call from someone who tells him a way to get back home. (Source: Viu)

The serial killer kidnaps Na Young. Her life is in danger. All the clues in her kidnapping are the same as the incident that happened in 2018, but this time, Han Tae Joo won’t let him get away. Na Young has been missing for over nine hours, and the detectives are put to the test to save her life. Will they find her in time? (Source: Viu)

Han Tae Joo still remains in the year 1988 even after the serial murder case of Kim Hyun Seok concludes. For their role and duty, the detectives of the Seobu Police Department are ironically faced with a transfer. Captain Kang Dong Cheol is outraged by this, and he seeks to find out answers only to find himself in trouble. Meanwhile, Han Tae Joo receives a call that might help him find his way back home. (Source: Viu)

Captain Kang Dong Cheol is a suspect in the death of Officer Shin and Chief Kim Gyeong Se. As a fugitive, he can only rely on Han Tae Joo to prove his innocence. Despite the evidence all pointing to Captain Kang, Han Tae Joo still tries to help him. Meanwhile, Chief Ahn Min Sik is determined to arrest Captain Kang Dong Cheol and won’t let off one bit. (Source: Viu)

Han Tae Joo wakes up in a hospital bed confused but back in 2018. He finally makes it back home where the people he had heard throughout his dream welcome him back. Han Tae Joo pieces back the fragment memories of his dream and starts to pursue the killer, Kim Min Seok, again. Meanwhile, Kim Min Seok strikes again, only this time, his method leads him to his demise. (Source: Viu)

After putting an end to the serial killings and finding closure for his father’s death, Han Tae Joo now understands the fate of his friends of the Insung Seobu Police Department that are back in 1988. He’s told the apparitions he is seeing are just a side-effect of the brain surgery he’d undergone, but to him, they couldn’t be more real. He is only left to yearn the familiar faces in his dream and to distinguish what is real and what is a figment of his imagination. What will Han Tae Joo do now? (Source: Viu)