Criminal profiler who discovers a walkie talkie connecting him to the past. He collaborates with a detective from the 1990s to solve a 15-year-old kidnapping and murder case, later helping to form a cold case team and investigating the mystery surrounding his partner's disappearance.
Communicate through walkie-talkie across time to solve crimes
Soo-hyun leads Hae-young in the cold case team
Potential romantic connection
Connected through the cold cases
Sun-woo appears to be a younger version of Hae-young
Work together on the cold case team
Work together in the police force
Colleague in the cold case team
Mysterious connection to the past cases
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