In "Signal" Kim Hye Soo's life ended up being dependent on Jo Jin Woong.
On the episode of tvN Friday/Saturday drama "Signal" (script Kim Eun Hee, director Kim Won Suk) broadcast on Feb. 6th, Soo Hyun (played by Kim Hye Soo) suffered a death. She was trying to rescue Shin Yeo Jin, the daughter of a construction company president and she suffered a death from the LPG explosion.
On this day, Jung Tae (played by Jung Suk Yong) caused an explosion by LPG gas in a car that had a freezing component. The thought was that because Yeo Jin had been alive in the Hanyoung bridge demolition incident instead of Eun Ji (played by Park Shi Eun), he thought that he was going to have her father suffer the same.
Soo Hyun who didn't know anything found Yeo Jin and turned on the freezing car. As the car turned the light on, the gas exploded and Soo Hyun faced death.
However, all hope wasn't lost. Such was because the Jae Han of 1995 was trying to catch the actual culprit. If this happened, then the same incident would not occur in 2016.
Meanwhile, "Signal" is about two detectives - one from the past and one from the present who communicate through walkie talkies to resolve long-time unresolved cases.