With 2018 marking the 10 year anniversary of the Marvel Cinematic Universe, it's fitting that the new year kicks off with one major Marvel milestone: Clark Gregg's first directorial effort in the MCU will air as this Friday's Marvel's Agents of SHIELD , four movies and five TV seasons after the actor first made his debut as SHIELD agent Phil Coulson in 2008's Iron Man.

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It's an opportunity that's a long time coming for the actor, and it's fitting that the on-again, off-again on-screen Director of SHIELD would become a real-life director of SHIELD as well."It's a big episode with some big stuff, and they really went with my ideas," Gregg told IGN several days before the debut of his episode, titled "Fun and Games." "Coming from indie film, I've really done something that's at the farthest end of different and still is the same concept. It was like doing a mini-Marvel movie. It's that episode, as people will see, that's a little bit like our version of Downton Abbey-meets-a very bloody, sci-fi version of Gladiator."Gregg's been the defacto leader of the network's flagship Marvel series since resurrecting Coulson in Agents of SHIELD's 2013 debut on ABC. But despite the show's executive producers offering Gregg the opportunity to direct an episode year after year, Gregg passed until Season 5.On the crisp Friday in September when IGN was invited to observe Gregg's directorial debut, you wouldn't have guessed that he ever had any reservations about shifting behind-the-scenes. That day they were filming a big fight scene between Chloe Bennet's Daisy and one of Season 5's new Kree villains, with Bennet filming take after take of a reaction shot.Gregg kept things light and playful on set, and was repeatedly open to his fellow cast members' suggestions even as director; when Bennet suggested that Daisy would act differently than what he suggested, Gregg's response was an excited, "Oh, that's a really great point.""It’s a big fight for me, so it’s really fun to get to be directed by [Clark]," Bennet told me in a break between takes. "Fights take so much time, so it’s just kind of fun being with [him] -- he’s one of my best friends. So it’s fun just getting to work with one of my best friends in a [new] way.""He’s been adding this really great texture to certain scenes, and really funny beats, that I don’t think someone else would be able to," she added.To hear his costars tell it, Gregg has always doubled a bit as a director on set, even when he was in front of the camera. "He’s been kind of -- not in a way that takes away from the director of the day -- but he’s always kind of directed scenes when we’ve been around him," Iain de Castecker told me during a break after a big Fitz scene. "You always look to him for guidance about something, if something’s not working. So, it kind of feels like a natural fit, doesn’t it?""Really natural," co-star Elizabeth Henstridge, who plays Simmons, agreed while standing backstage on the studio lot. "We just feel very spoiled because we have such a shorthand with him, and, you know, he’s one of us. We’ve had some really good conversations about character, and he obviously knows so much about everybody’s journey that it’s, yeah, very natural.""Fun and Games" will see the culmination of the big Fitz cliffhanger at the end of "A Life Earned," and according to Caestecker, there was no one better than Gregg to be behind the camera for the major plot developments that are ahead in this episode."There’s a lot of beats that are significant character-wise with characters that have been going on for five seasons now which Clark really understands," he teased.Though it might seem strange that Gregg was so hesitant to get behind the camera given his history as a film writer/director, it's his work in indie film that had him dragging his feet to helm Agents of SHIELD despite the repeated offers of EPs Jeff Bell, Jed Whedon and Maurissa Tancharoen. He wrote and directed both of his two features (the 2008 adaptation of Chuck Palahniuk's Choke, and 2013's Hollywood dramedy Trust Me), neither of which required him to fit his style into a franchise 10 years in the making."I would watch the episodes [of SHIELD] be directed and I would go, 'This is so different from anything I've done,'" said Gregg. "The role of a director of a television show is very different than when you're making an indie film and you wrote it or you adapted it, and you are rewriting it on the fly and you're the sole voice. You're not trying to fit into an existing thematic style [or] visual style. It's a very different beast."Despite working on multiple Marvel features films and five seasons of the show, Gregg was still unprepared for the process that makes the tight turnaround for a comic book TV show episode a reality. He spoke to SHIELD directors Kevin Tancheron, Billy Gierhart and Jesse Bochco prior to filming to get tips on what he should do and shouldn't get hung up on, and brought a good amount of his own humor and understanding of these characters to the mix."They've got it so that it's a perfect little Marvel movie boot camp, all compressed. In a way it's harder because it's so compressed, but the way that they're able to help you understand the way it's going to work in a scene and how [visual effects supervisor] Mark Kolpack is able to adjust what he plans to do with the visual effects given the budgets to my ideas, it was really just a thrill," he said."I really wanted to find a way to take the things that I love in some of those episodes -- the ways of telling a story, a lot of fast-moving cameras, the comic book feel -- and also keep some very heavy moments that happen leavened at times with the Joss/Favreau model of tremendous drama followed by a joke," Gregg added, noting, "My job was not to turn this into something that felt like my films; it was really to just get the most out of that particular episode because I was doing something so different from anything I've ever done."

Terri Schwartz is Editorial Manager of Entertainment at IGN. Talk to her on Twitter at @Terri_Schwartz