When Detective Moo Jin Hyuk's wife is brutally murdered, Kang Kwon Joo, an officer with superior auditory abilities, listens on the other end of the 911 call. Three years later, Jin Hyuk and Kwon Joo find themselves working together.

Jin Hyuk rushes to get to Bok Rim before it's too late. Kwon Joo compiles officers with varying expertise for her Golden Time Team.

Time is running out for Ah Ram as Kwon Joo tries to decipher the xylophone sound. Kwon Joo tells Jin Hyuk her side of what happened three years ago.

When Go Dong Chul's death is ruled a suicide, Kwon Joo realizes she must take things into her own hands. Jin Hyuk hurries to find the victim, whom he knows personally, of a kidnapping case.

The clock is rapidly ticking for Kwon Joo as her captors prepare to bury her alive. Meanwhile, Eun Byul's own life is in danger as she's hidden in a location unknown to the police.

Kyung Il reveals to Kwon Joo that he witnessed her father's murder. Jin Hyuk and Kwon Joo go off on their own, feeling closer than ever to finding the perpetrator.

When a dead body falls out of a supposed victim's closet, Jin Hyuk and Kwon Joo realize the case goes much deeper than they had initially expected.

Jin Hyuk tries to escape the clutches of Good Friend, who don't quite live up to their name. The hunt for the perpetrator continues, but he is not an easy target.

An accusatory post about Hyun Ho appears online. The Center receives multiple calls when a night club suddenly turns into a nightmare.

Yang Ho Shik ambushes Eun Soo while Jin Hyuk and Dae Shik are led astray. Things become even more personal when Dong Woo is put in danger.

The elusive Nam Sang Tae prepares to flee the country, but the police are determined not to let him get away this time. A 911 call brings the Golden Time Team to a hostage situation on a rooftop.

Kwon Joo realizes they may have written off Baek Jin Gu's claims too quickly. Later, she finds troubling information related to the Eunhyung-dong case.

Jin Hyuk goes to meet Nam Sang Tae by himself, hoping for answers. Kwon Joo looks deeper into the relationship between Ji Hye, Kong Chul Hwan, and GP Development.

All hell breaks loose when Kwon Joo recognizes Tae Gu's voice. A serious bus accident threatens the lives of many, including a pregnant woman and a child.

As gas continues to leak from the bus, the chance of an explosion heightens. Jin Hyuk must face the undeniable truth about Dae Shik.