Hae-young finds an old walkie-talkie in the corner and gets clues on the unsolved kidnapping case.
Hae-young joins the unfinished case squad and Jae-han says something through the walkie-talkie.
Hae-young is confused after discovering that the talks through the walkie-talkie changed the past.
The squad starts investigating the Gyeonggi Nambu case despite the opposition from their superiors.
Hae-young gets one step closer to the truth of the disappearance of Jae-han.
Hae-young continues to make an effort to change the wrongly intertwined past and future.
Lee Je-hoon
Park Hae-young
Kim Hye-su
Cha Soo-hyun
Cho Jin-woong
Lee Jae-han
Jang Hyeon-seong
Kim Beom-ju
Jung Hae-kyun
Ahn Chi-su