If you're not watching the new season of Mayans MC on FX, it's time to catch up. Not only is the Sons of Anarchy club rearing its ugly head once again, but there was a very surprising face that popped up in the latest episode. The new season of Mayans is one of the most turbulent yet, with an internal grudge ripping the titular club apart at the seams and seemingly no hope on the horizon.

　　Warning: The following contains spoilers for the fourth episode of Mayans Season 4, "A Crow Flew By." If you haven't watched it yet, stop now.

　　While the Sons of Anarchy have approved going to war with the Mayans over the dead Son from way back in Season 2--and the club is currently at war with itself--one of the most interesting moments came in the form of a new character introduction. AEW wrestler CM Punk, who has also appeared on Starz' Heels, has officially entered the Mayans MC universe.

　　At a barbeque with his fellow military veterans, Gilly (Vincent "Rocco" Vargas) sits at a table with a friend from his time in the service--and that vet is played by none other than Punk. It's an interesting scene that explores the dynamics of the lives of veterans and will likely be continuing in some form throughout the rest of the season. After all, Mayans MC showrunner Elgin James confirmed to GameSpot that this isn't Punk's only appearance on the show.

　　What you might be wondering, though, is how on earth this casting came to be. As it turns out, James and Punk (Phil Brooks) run in the same circles.

　　"Straight edge, bro," James explained to GameSpot. "We're both on the straight edge world. We met a few years ago and I was just like, 'Yo, I gotta do something with this dude. We gotta find something.'"

　　Fast forward to Season 4 of Mayans, and James and his team built this role specifically for Punk. "We kind of crafted this for him actually," he said. "We knew we wanted to get into the storyline with Rocco and to do right by the veterans. And then we kind of were like, 'well, what are the right ingredients to tell this story? And then this is a perfect opportunity to finally work with Phil. He's the man."

　　And, thankfully, he's just what the show needed. Given Vargas's history as a soldier in the US Army for over a decade, it's important to both James and the actor himself to explore the lives of veterans properly. According to the showrunner, that included Vargas and other veterans that work for the show sharing their stories with the cast on the day of shooting.

　　"They knew the heft of what they're going to bring on and it was really emotional before that first day of shooting, Rocco talked to him for about an hour,'" James said. "We had some other veterans with us that are also on the show and that you've got you saw in there. And it's pretty beautiful, they're talking about their experience coming back and some of the challenges they face. So the weight was on Punk's shoulders to do this right. And of course, there's no one else you want that weight on because that dude's just a savage. He just brought it, not only physically but also emotionally."

　　Mayans MC airs Tuesdays on FX.