‘Marshals’ Star Mo Brings Plenty Seeks Justice for Nephew After ‘Murder’

Mo Brings Plenty, an enrolled member of the Lakota Nations, was frustrated with the cultural misappropriation that he saw onscreen until Yellowstone came along. Thanks to a collaboration with prolific hit-maker Taylor Sheridan, not only did Plenty land a role in the mega-hit series as the right-hand man to Broken Rock Tribe chief Thomas Rainwater (Gil Birmingham), he was also hired behind the scenes as the show’s American Indian Affairs coordinator. And it’s a role he’s now continuing on the CBS Yellowstone spinoff Marshals, which follows Kayce Dutton (played by Luke Grimes).

Marshals has become a huge success for the network, repeating as the top series — network or streaming — two weeks in a row. Below, when chatting about Sunday’s fourth episode of the hit season (it’s already been renewed for season two), Plenty speaks with The Hollywood Reporter about both his onscreen role — as Mo (also the name of his character) — and the authentic input he gave behind the scenes in season one.

He also opens up, for the first time in an interview, about the untimely death of his nephew, Cole Brings Plenty, a star in the Yellowstone-verse who was found dead between seasons one and two of the prequel series 1923. “For his murder to go uninvestigated, and for it to be written off as ‘no foul play,’ because they didn’t want to invest anything into it? It’s heartbreaking,” he says. “We’re not letting it go.”

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When were you first approached about being a part of Marshals?

I received a call from my team, and I said, “Absolutely. If Luke [Grimes] and Gil [Birmingham] are involved, I’m in.” It was an easy yes to carry on these characters. These are such iconic characters and I so desired to carry them on. I was kind of sad when we were finishing up Yellowstone. Those were some amazing guys. And then all of a sudden, here we are. We’re back. It was just great news to me. I was doing cartwheels in my mind and a happy dance that I would not want the world to see (laughs).

We spoke to star Luke Grimes and your showrunner Spencer Hudnut about how they had to find the right way to reopen Kayce Dutton’s story since Yellowstone gave him such a beautiful ending, especially involving your character with the Duttons giving the land back to the Broken Rock Reservation. Did you have any hesitations about revisiting that ending?

I didn’t have any reservations, especially knowing that Luke was going to be involved, and Gil. Obviously, Luke isn’t going to just sign up for something that wasn’t going to be good for those characters, and Spencer too. Getting the opportunity to work with him, I can’t say enough good things about him. It’s like I never left. It’s like being back home. I’m just so thankful for this opportunity to carry him on.

How did you react when you found out that the hook to the show would be that Monica Dutton [Kayce’s wife, played by Kelsey Asbille] dies?

Boy. At first, I was like, “Why?!” Because that was our connection to the Duttons. There’s always been a connection between the Dutton family and Broken Rock, but Monica was more of a connection. So to lose that, at first, my reaction was like, “No.” But we gotta tell a story. And the blessing of that occurring is that Kayce has to fill that void now. So that connection is still there. Not just for the fact that Rainwater adopted and took him in as a brother, but I think the warriors that Mo and Kayce are, that brotherhood has always been there, but it’s become even stronger.

They could have continued this story without Broken Rock. How happy are you that they went this way?

I’m ecstatic. I’m so extremely grateful that they didn’t leave Broken Rock out of it, and that they didn’t leave Indian Country out of it. They could do whatever they want. But if you want layers and diversity, what better way than to incorporate the original inhabitants?

Spencer said that Kelsey Asbille wasn’t available for Marshals, so he wasn’t involved in the conversations about her not being a part of the show. Have you spoken to her at all?

You know, no. I haven’t spoken to her. I thought about reaching out to her at the very beginning. But that was before I found out [the plot]. I just left it alone. I mind my business and do my job to the best of my abilities.

Spencer said Monica’s death, obviously, serves two purposes. It’s the hook for the show, but it also shines a light on something real happening on reservations. Did you have any input in this storyline, or did they come to you with this idea? [Note: Monica died after battling cancer due to toxic levels in the water on the reservation.]

This was already there. And I’m glad we’re going to be able to bring this to light, not just with the reservation, but water is life for everyone. And when I say “everyone,” I’m talking from the vegetation all the way to the human race. I’m thankful that we’re bringing this to light.

I’m sure you were thrilled that Mo would be a character on the show. When they said, “We also want you behind the scenes to help us keep telling res stories,” how did that conversation go? Was their goal to continue what Taylor Sheridan had started with Yellowstone in that respect?

I’m so filled with gratitude for the opportunity, not just to carry on the role of Mo, but to be able to continue on in the American Indian Affairs coordinator role, and have input in storylines. There was a time when our ceremonies were never hidden. It wasn’t until they were banned that they went into hiding. And then in 1976, when President Jimmy Carter signed the American Indian Religious Freedom Act, it gave us the ability to practice our ceremonial ways again. It’s been trying over the years to allow that part to exist in everyday life. Now we’re bringing different elements to the forefront and showing the world that we, as American Indian people, still have our traditional ways. We still have our way of prayer. We still have different things we can do to help us through grieving and through different aspects that continue to inspire.

Spencer said the mine story will continue throughout the season, and that there will be other episodes, including when children go missing from reservations. What were some storylines you contributed to or authentic changes you made?

I contributed to a particular moment in the grieving process for [Monica] for Kayce and [son] Tate. I contributed, along with my younger brother, in providing a moment. It hasn’t aired yet, so I don’t want to describe it yet. It’s a beautiful moment. So to be able to contribute in that way — even in songs. My brother composes a lot of the songs that we utilize not just in Yellowstone, but also on Marshals, that fit a particular scene that we’re going. To be able to carry that on is so important. I’m thankful to Spencer, who’s open and understanding. It’s like working with Taylor again. Spencer and I are kicking around ideas that I don’t even want to reveal yet. But there are going to be some beautiful things coming up.

This week’s episode introduces a possible romantic interest for Kayce. Spencer hinted about exploring new relationships with Kayce as the season moves on. How will the show, even as it goes on to season two, continue to honor what Monica and Kayce had as such a core Yellowstone couple?

What Kayce and Monica had, that relationship, is going to be carried on. That relationship existed so strongly. It wasn’t just about a husband and wife. It was also a relationship between the Duttons and Broken Rock. I feel that Rianwater and Mo are going to be able to carry on that relationship and build upon what they have established. Monica was a strong warrior. She made great sacrifices to protect people. Even jumping back to Yellowstone with the individual who was the rapist, Monica set that up. She was the bait, so to speak, and was able to help seize that individual. The spirit of her is always going to remain.

Yellowstone skeletons haunt Kayce. The sins of his family have been a big part of these first episodes. Spencer said Yellowstone will continue to be a part of this show. How would you say the Dutton name continues to loom over Kayce, or will he be able to get out from the shadow?

I think Kayce is such an amazing individual that the Dutton family will end up existing within his shadow. I believe he will crawl out from underneath the shadow of his family, and he will cast his own shadow. He’s a strong individual, a great warrior. Bottom line. But he thinks differently. He has a different mind. And so I believe he’s going to be able to cast his own place so that will no longer be in the Dutton family shadow.

How big a role will Mo have as the season goes on? Anything you can tease?

People are going to get to see a little bit more of who my character is. Just about who he is to the people, to Broken Rock. We filmed the first season. I have no idea [beyond season one]. It’s entirely up to the writers. I would like to hope that the character will grow some more. I respect every decision that is made, and I respect the story. It’s about the audience. It’s not about my character.

I was so sorry to hear about your nephew, Cole Brings Plenty [who died in 2024 at age 27], and I want to share my condolences with you and your family. He had such a beautiful role in 1923. Is there anything you’d want to say to pay tribute to him?

Absolutely. He was our future. He knew our ceremonies. I was teaching him more and more, so was my brother, his father. He was my nephew, but he was like a son to me. And for his murder to go uninvestigated, and for it to be written off as “no foul play,” because they didn’t want to invest anything into it? It’s heartbreaking. Because we’re taxpaying people as well. So for them to not work for us, no different than how they work for anyone else is, is pretty sad.

I hope that we continue on to talk about that in our storylines — that there are a lot of families such as mine that are going through this right now, and we still have a lot of unanswered questions. Because I saw his body, I saw the evidence that is there that someone caught him. So for them to say that there was nothing, I can’t believe that. I still can’t.

I didn’t know that. There hasn’t been much released about that.

The departments didn’t put much effort into it. In fact, they weren’t even really looking for him. They were hunting him. They weren’t searching for him. They were hunting him until the day when a good friend of mine and I rented a helicopter and told the Lawrence Police Department [in Kansas] that we were going to go and search from the air, and that day, they were out in full force.

Is there anything you’re still doing to bring him some justice?

Just spread the message. We’ve been in talks with several different people. We’re not letting it go. It was a hard loss for us because this was an individual who was speaking our language, singing our songs and carrying on our traditions. He was the future for us. We want more and more of our young people to be inspired to pick up who we are from a cultural perspective.

You have a large audience on Marshals. I’m sure you saw the ratings and the early renewal. Will you feed some of this into the storylines?

I hope so. We’ve kind of already touched on it, and if it weren’t for Kayce being with the U.S. Marshals, it just goes to show the importance of working together. And how vital that is and how meaningful, and how helpful that would be to the families.

Taylor Sheridan has created a large platform for these stories to be told. Since you’ve been in this role since Yellowstone started, do you feel like you’ve seen more or less of others doing similarly?

I think Taylor was a catalyst to more people having the courage to tell those stories. And so I’m thankful for that.

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Marshals airs new episodes at 8 p.m. on CBS.