Signal poster

Signal

★ 8.4 13K votes 2016–2016 1 season · 16 episodes Ended tvN
Time travelTime manipulation as a core mechanic.This show: 9/10Detective mysteryCrime-solving from the investigator's side of the table.This show: 9/10K-dramaKorean drama storytelling: emotional arcs, romance beats and format traditions.This show: 8/10SerializedContinuous arcs where every episode builds on the last.This show: 8/10TenseSustained suspense and pressure from start to finish.This show: 8/10BittersweetJoy and loss mixed so thoroughly they can't be separated.This show: 7/10Mystery boxCentral riddles sustained across whole seasons.This show: 7/10Emotionally heavyDemands real emotional stamina from the viewer.This show: 7/10
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Starring
Lee Je-hoonKim Hye-suCho Jin-woongKim Won-haeJang Hyun-sungJung Hae-kyun
Starring
Lee Je-hoonKim Hye-suCho Jin-woongKim Won-haeJang Hyun-sungJung Hae-kyun
Ratings per Episode
246810
Votes per Episode
0100200300400

Signal Episode Ratings Heatmap

AvgE1E2E3E4E5E6E7E8E9E10E11E12E13E14E15E16
S17.97.97.97.98.27.37.77.58.47.98.17.78.18.17.98.17.5

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About

"Cold cases solved across a decades-wide radio silence"

A present-day detective stumbles on an old walkie-talkie that somehow lets him talk to a cop working the same cases decades earlier. Together they start solving cold cases that were never closed, but every fix in the past risks changing the present in ways neither expects. It plays like a moody procedural crossed with a time-bending mystery: methodical, melancholy, and tightly plotted, with the case-of-the-week structure gradually building into one long thread about justice, guilt, and whether the past can actually be repaired.

Watch it for

the way each solved case ripples forward and complicates the present in unexpected ways.

Maybe skip if

you want fast, flashy thrills rather than a slow-burn, melancholy mystery.

Written by our AI editor to help you decide, spoiler-free by design.

All Seasons

▼
Season 12016
7.94K1615h 27m
Communicating via a walkie-talkie that transcends time, a profiler from 2015 and a detective from 1989 join forces to tackle crimes and injustice.
EpTitleRatingYoursVotesRuntime
▶1You're Doomed7.9
33676 min
▶2We Still Have a Chance7.9
27865 min
▶3We Can Prevent the Killings7.9
252—
▶4We Found the Killer8.2
26664 min
▶5Changing the Past Alters the Present7.3
22867 min
▶6Catch Him by All Means7.7
22170 min
▶7We Must Dig Deeper7.5
20966 min
▶8How Are You Alive?8.4
22574 min
▶9Hongwon Dong Case7.9
21173 min
▶10Someone Has to Stop the Bad Guys8.1
209—
▶11The One Last Case7.7
20377 min
▶12The Case Was Manipulated8.1
20177 min
▶13The Real Assailant8.1
20573 min
▶14Not Now, But Maybe In The Past7.9
19474 min
▶15Is It Really You?8.1
19971 min
▶16If You Don't Give Up7.5
225—

Full Cast & Crew

Cast

Lee Je-hoon Park Hae-yeong
Kim Hye-su Cha Soo-hyeon
Cho Jin-woong Lee Jae-han
Kim Won-hae Kim Gye-cheol
Jang Hyun-sung Kim Beom-joo
Jung Hae-kyun Ahn Chi-soo
Lee Yoo-Joon Jung Hun-Gi
Jung Gi-sub Choi Seok-won
Eom Ji-man Kim Hae-chul (Detective)
Lee Moon-soo Lee Cheol-yong (Father of Detective Lee Jae-han)

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