tvN Sets December 7 Premiere for Second Signal After AI Replacement Tests Fall Short

Eight episodes will air after months of uncertainty

tvN will premiere Second Signal on December 7, 2026, at 10 p.m., ending an indefinite scheduling delay linked to actor Jo Jin-woong's past misconduct. The broadcaster said it tested replacing a performer with artificial intelligence but found that the results could not preserve natural acting and the flow of the story.

The announcement on November 6 sets out an unusual opening schedule for the eight episode sequel: episodes 1 and 2 will air consecutively on December 7, followed by episode 3 on December 8. Part of the first episode will be shortened or adjusted. After the opening week, the drama will continue with one episode each Monday and Tuesday.

Second Signal had originally been planned for June as a production marking tvN's 20th anniversary. Filming finished in August 2025, before the controversy that led Jo to announce his retirement from acting in December that year.

tvN's decision brings together three connected issues: how to respond to concerns about a leading actor, whether technology can remove that actor from a completed drama, and what should happen to the work of everyone else involved. The channel acknowledged the seriousness of the actor's past while arguing that the production should be considered as a collective creation.

What viewers will see in the opening week

December 7 will carry two episodes rather than the single episode that will become the regular pattern. tvN said it would reduce or adjust part of episode 1 while preserving the story's continuity and the audience's involvement.

Episode 3 follows the next evening, bringing the opening week's total to three of the drama's eight episodes. That is 37.5 percent of the series by episode count, although the shortened premiere means it is not necessarily the same share of total running time.

tvN described episode 3 as the point where the main story begins in earnest. Its schedule therefore takes viewers through the opening setup within two evenings before switching to the regular Monday and Tuesday pattern.

The 10 p.m. start is later than the slot previously envisaged. tvN attributed that choice to the drama's genre and viewing conditions. It did not specify the number of minutes being removed from episode 1, the precise scenes affected, or the combined running time of the first night's broadcast.

Why tvN decided to release the drama

tvN said its deliberations covered the production from initial planning through filming and postproduction, the stage when footage is edited and prepared for release. Its central argument was that a completed television drama represents the work of many people, rather than a single performer.

The broadcaster, explaining its decision in its official statement, said:

We believe there is a need to distinguish between assessments of an individual cast member, the value of the work itself, and the efforts of the creators who took part.

Actors, production staff and others had already contributed their time to a series whose filming was complete. tvN also cited viewers who had waited for the sequel. Those considerations formed its stated reason for giving the production a broadcast slot despite continuing concerns.

The channel acknowledged that announcing a release would not resolve every objection. Its position leaves viewers with a concrete choice in December: whether to watch a returning drama whose central cast still includes the actor at the heart of the controversy.

tvN's full official announcement

The full statement, translated from Korean, reads:

Hello, this is tvN.

"We take seriously the concerns and opinions viewers have shared regarding the drama Second Signal.

"The wrongful past conduct of a particular cast member is an issue that we, as a channel, can by no means take lightly. However, Second Signal is not the work of one particular cast member alone. It is a collective creation containing the time and effort of many staff members, production team members and others involved, from the planning stage through filming and postproduction. We believe there is a need to distinguish between assessments of an individual cast member, the value of the work itself, and the efforts of the creators who took part.

"Accordingly, after long deliberation and with a cautious heart, we intend to schedule Second Signal as a tvN Monday-Tuesday drama starting December 7. Taking into comprehensive consideration the work's genre characteristics and viewing environment, we plan to broadcast it at 10 p.m., a later nighttime slot than the existing time. Also, considering the development of the eight-episode drama and the overall viewing flow, we will air through episode 3 in the first week. On the first broadcast day, we will partially shorten and adjust the running time of episode 1, within a range that preserves the story's flow and immersion as much as possible, and schedule episodes 1 and 2 consecutively. The following day, we plan to broadcast episode 3, where the story begins in earnest. Thereafter, we will continue broadcasting one episode each Monday and Tuesday.

"Before reaching this decision, we examined various ways to minimize concerns while maintaining the quality and completeness of the work. We explored revisions using video technology and also conducted tests using AI to replace a person on screen. However, there are limits to reproducing acting and the narrative flow naturally, making final application of the technology difficult.

"We wish to make clear that releasing the work does not mean endorsing or justifying the problem. Although this decision may not resolve all the concerns you have shared, we judged that we must also consider those who have waited a long time for the work and the efforts of the many actors, staff members and production team members who have done their utmost in their respective roles to complete it. We will convey the original story and meaning of Second Signal in a worthy way, while not forgetting our responsibility as a channel.

Why the AI replacement was abandoned

tvN examined changes using video technology and conducted tests involving artificial intelligence, or AI, to replace a person on screen. The broadcaster said it was looking for ways to reduce concerns while maintaining the quality and completeness of the drama.

In its explanation of the technical decision, tvN said:

There are limits to reproducing acting and the narrative flow naturally, making final application of such technology difficult.

The problem described by the channel involved both performance and storytelling. An actor's contribution includes expressions, gestures and interactions with other performers. Those elements need to remain convincing from one shot to the next for a scene to work.

Jo plays detective Lee Jae-han, a central figure in the story, and has substantial screen time. Removing a central character presents a different editing problem from cutting an isolated appearance: scenes involving that character also carry information and relationships needed elsewhere in the drama.

The tests left tvN proceeding with a production built around the filmed performances, alongside the announced adjustment to the opening episode. The broadcaster's explanation places the limit at the point where the proposed technical changes affected the natural performance and continuity it wanted to retain.

The allegations, agency response and retirement

Jo's past became a public controversy in December 2025. Allegations included vehicle theft during his youth and claims that he had been sent to a juvenile detention facility. Saram Entertainment, his agency, confirmed that he had engaged in wrongful conduct as a minor and apologized, while denying any connection to allegations involving sexual violence.

The controversy also brought attention to accounts of an assault on a theater colleague resulting in a fine and a driving offense involving alcohol that led to the cancellation of his license. The agency's acknowledgment concerning his youth was expressed in general terms.

Jo subsequently announced that he would stop his activities and retire from acting. In his retirement statement, the actor said:

I will humbly accept all reproach.

His departure came after Second Signal had been filmed, leaving the broadcaster and production team to decide how to handle a finished series featuring him in a major role. The drama's focus on criminal investigations also made his participation a particular point of public concern.

A returning cast and a story across time

Second Signal follows Signal, which aired in 2016. Writer Kim Eun-hee returns for the sequel, directed by Ahn Tae-jin, whose previous work includes the film The Night Owl. Lee Je-hoon and Kim Hye-soo return alongside Jo from the original cast.

The series connects detectives in the past and present through a walkie-talkie as they investigate cold cases. A cold case is an investigation that remains unresolved for a long time. The radio connection allows officers living in different periods to exchange information about those investigations.

Jo's detective Lee Jae-han is part of that central storytelling structure. His role helps explain why discussions about removing his footage or replacing his performance became tied to the fate of the whole series.

The sequel arrives a decade after the original broadcast. tvN had prepared it as an anniversary production, making the delayed release both a return for an established drama and a programming decision involving a project the channel had already placed within its 20th anniversary plans.

How the release moved from June to December

The production's chronology shows why the broadcaster faced a decision about completed footage rather than casting a role before filming. Shooting ended several months before the controversy became public, and the initial June broadcast plan was subsequently put on hold.

• 2016: Signal airs, introducing the drama that Second Signal continues.
• August 2025: Filming of the sequel is completed.
• December 2025: Allegations about Jo's past emerge, and he announces his retirement.
• June 2026: The originally planned anniversary broadcast does not go ahead.
• November 6, 2026: tvN announces the December release and explains its unsuccessful AI replacement tests.
• December 7, 2026: Episodes 1 and 2 are scheduled to air consecutively, starting at 10 p.m.
• December 8, 2026: Episode 3 is scheduled to air, before the series moves to one episode each Monday and Tuesday.

October discussion of a possible December slot had been met with tvN's position that nothing was decided. The November announcement replaces that uncertainty with a date, a start time and a specific plan for the first three episodes.

tvN also addressed its responsibility for the decision. The broadcaster said:

We will convey the original story and meaning of 'Second Signal' in a worthy way, while not forgetting our responsibility as a channel.

Key Points

• Second Signal premieres on tvN on December 7, 2026, at 10 p.m.
• Episodes 1 and 2 air consecutively on the first night, with episode 1 partly shortened or adjusted.
• Episode 3 follows on December 8. Later episodes air individually on Mondays and Tuesdays.
• tvN tested AI replacement but cited problems preserving natural acting and story flow.
• Jo Jin-woong announced his retirement after controversy over his past. Filming had already finished.
• Kim Eun-hee writes the sequel, Ahn Tae-jin directs, and Lee Je-hoon and Kim Hye-soo return.