Netflix's drug cartel series is shifting away from leading man Pedro Pascal. "The continuing character on 'Narcos' was always intended to be cocaine," showrunner Eric Newman exclusively tells THR.

Narcos will be going back in time to explore the origins of its next threat in the drug war: Mexico's Guadalajara cartel.

The Netflix drug cartel series has added two new stars for its fourth season, Michael Pena and Diego Luna, and will be set in Mexico City to explore the rise of the Guadalajara cartel, the first Mexican drug trafficking group to sync up with the Colombia bosses in the cocaine trade. Though Pena and Luna's roles have not yet been revealed, the move to Mexico signals the end of main character Javier Pena's story — and a phasing out for Narcos leading man Pedro Pascal.

Up until now, the series has been shot entirely in Colombia to track the original cocaine king, Pablo Escobar (played by Wagner Moura), and the successors to his Medellin cartel, Cali. The four Cali cartel bosses were the villains in season three and their deaths and incarcerations brought the Narcos timeline up to the mid-1990s.

"The origins of the Guadalajara cartel are in the late 1970s and early 1980s, so Narcos is going back in time," showrunner Eric Newman told The Hollywood Reporter about the season four announcement, made on Tuesday. Netflix released a video of the new theme song (below) along with the casting and location news; the season launches in 2018.

This is not the first cast reset for Narcos. Star Boyd Holbrook exited the series after two seasons when the real-life timeline of his character, DEA agent Steve Murphy, caught up to the show's. The series then took liberty with his partner's story to keep Pascal in a starring role as DEA agent Pena for season three.

Narcos' move to Mexico was first reported in September when a location scout working on the fourth season, Carlos Munoz Portal, 37, was found dead in his car northeast of Mexico City in a high-crime area. According to local reports, his body and car were riddled with bullets. Though an investigation is still ongoing, Newman confirmed what THR had reported, that his death is not believed to be connected to the show according to local law enforcement.

Below, in an exclusive chat with THR, Newman goes inside the creative decision to shift Narcos to Mexico, including the safety precautions taken on set in light of the tragedy; compares the Guadalajara cartel (where Joaquin "El Chapo" Guzman got his start) to season one and two’s Escobar story and his season three Cali successors; and discusses exiting star Pascal, along with the show's future.

Where are you in production on season four now?

We are already underway and have filmed the first two episodes. We’re about to start shooting episodes three and four. We’re shooting in and around Mexico City as well as a number of other cities around the country. Authenticity is so important to us, and for the same reason that we had to do the Medellin and Cali cartel stories in Colombia, we felt we had to do the story of the Guadalajara cartel in Mexico.

Carlos Munoz Portal was killed while scouting locations for season four. How did his death impact the set and production?

It was a terrible tragedy for all of us. There were obviously several ramifications. First, the emotional toll of losing a member of the team, particularly one as well-liked and respected as Carlos, weighs very heavy. We had just started preproduction when it happened and so it was a rude awakening and ominous beginning for the dozens of crew who had begun the process of relocating the show. It rattled a lot of people, frankly. We certainly had to pause a moment, mourn and then carefully consider whether or not we could proceed safely in Mexico. We commissioned numerous security analyses and met with Mexican law enforcement officials and government at the highest level, and concluded together that the crime had nothing to do with Carlos' work on the show. There was no specific threat to Narcos. And, in fact, it’s very likely that the people who killed Carlos had no idea who he was working for or what he was doing there. It was clearly a terrible instance of wrong place, wrong time. But it did force us to evaluate our process and our security protocol to ensure the maximum degree of safety for our cast and crew. The Mexican authorities assured us that we were a priority and that they very much wanted us to continue working there. They saw this as an isolated occurrence, and I think everybody involved was able to look at each other and say that we should proceed.

What can you say about the status of the investigation into his death?

It’s ongoing and I can’t really comment further on the specifics of it.

You are also in a new location since the series thus far has been shot in Colombia. What precautions did you take?

We increased our security. We’ve made every attempt to operate only in the areas that we know to be safe. We have an incredible team of security professionals made up of Israelis, Mexicans and Americans. We feel like we can protect our crew.

Does it feel different shooting in Mexico City? Have you received any threats?

No. Never. Not before, not after. There have obviously been individuals who have sought to gain some attention with their statements about the show. These individuals sought to take advantage of a tragedy to try to increase their own profile. I find it both irresponsible and shameful. Despite this, there has never been a threat, credible or otherwise, made toward the show, either in Colombia or in Mexico. The many Mexican members of our cast and crew have told us that they are not concerned about safety. Diego Luna is one of the most beloved actors in Mexico and our cast has a number of other high-profile Mexican actors and no one has expressed concern.

At what point did you know you were taking the series to Mexico?

We always knew that we would get to Mexico eventually. A key team comprised of myself and the guys I really trust and work very closely with — [director] Andi Baiz, [co-creators] Carlo Bernard and Doug Miro — have been discussing how to best transition to Mexico as early as season two. We decided on the Guadalajara cartel because it represents the beginning of the modern Mexican drug trade. It makes sense to start there.

When did you know that you would retire DEA agent Javier Pena from the story, and with that decision, that Pedro Pascal would no longer be the star of the show?

It was a part of the plan as early as season two. The design was always to finish out the Colombian story and the players that we’ve come to know there, and then start anew in Mexico.

So, Pascal was aware of the plan and kept it a secret?

Yes. Although, he alternated between asking us to kill off his character at one point and then wondering, "Hey, maybe he can come back." I’d like to think that he still hasn’t made up his mind about whether he wants to come back. (Laughs.) It is after all an intersecting universe — the Mexicans did a lot of business with the Colombians.

Are you confirming, then, that he won’t appear at all in the upcoming season?

I’m confirming that it’s not about him.

The season three finale was somewhat open-ended with Javier Pena, where it wasn’t entirely clear if he wanted to go fight another drug war in Mexico after Cali. How should we interpret that final scene now?

We think more about the place than the people. Clearly, we suggest Mexico at the end of season three. The Guadalajara cartel was a force in the 1980s, concurrent with the Colombian cartels. So we will ostensibly be going back in time a little bit. The Mexican cartels started with marijuana and heroin and then got into cocaine, which they acquired from the Colombians. We see a little bit of that in season three with the character of Amado Carrillo Fuentes (aka Lord of the Skies) and his Juarez cartel. But reports that we would focus on Juarez in season four were inaccurate.

What does Narcos look like without Pascal and how do you describe what the series has become, with new stars and a new story being taken on each season?

The continuing character on the show was always intended to be cocaine and the futile war against it. Our characters are important, and there are a lot of similarities where, as we like to say, there are bad guys and very bad guys, but they are secondary to the cocaine. It’s about the ongoing war against drugs and against cocaine and the inherent, unwinnable nature of that conflict.

Why are Michael Pena and Diego Luna the right men for the job in season four?

First and foremost, they are both amazing actors. Michael is Mexican-American and Diego is Mexican, and that was very important for authenticity. They both responded to this particular story and they love the show. It’s not as short of a list as you think, but for us, the two of them were at the very top of it. We were thrilled to have them join us.

Will there be any recognizable faces?

It’s almost an entirely new group with some overlap and hopefully a few surprises.

How do the Mexican kings of cocaine compare to Pablo Escobar and Cali's reign in Colombia? What can be expected?

Everything about Mexican trafficking is closer to home. The proximity, the complexity of the relationship between the two countries. Colombia is a sort of remote place to most Americans, who have never been to Colombia or met a Colombian. It was easier to distance ourself from who we thought were the enemy. Mexico is our neighbor and so the ties are deeper.

You previously said the next chapter will require more of a looking inward into not only the supply but also the demand. Will you be tackling the U.S. role in the drug war?

It’s always a factor, given that we’re interacting directly across this border. The implication that this is not just about people sending us drugs that we don’t want is very much a part of Narcos.

How many seasons do you envision Narcos going?

I know we’d like to do more than four seasons and I know that we have the material. With history as a guide, we could go forever. Our M.O. is that we work very closely with people to whom these things happen, particularly on the law enforcement and DEA side.

This season, you are blowing up the series' chronological timeline so you can properly tell the Guadalajara cartel story. Is the longevity of the series now just a matter of how long it takes you to catch up to the present?

Yes. Even if we were to race through the story, it would still take a while to get to the present with the wealth of material that exists. We started the Colombian story in the late 1970s with Escobar. The Mexican cartel’s relationship with cocaine starts in the early 1980s — and what’s unique about the Guadalajara cartel is what they did organizationally. They really unified a large part of the trafficking world under one banner. They started it all and waited for the Colombians to fall before taking over the trafficking business. The frontline of the drug war is with the end users in the United States who continue to use and buy drugs, but we never seem to grasp that. Mexico is where we’ve chosen to fight it.