"I've watched directors since my very first day of acting because I knew I wanted to direct," he tells TVGuide.com. "I painstakingly paid attention to every move and every word. But I was really struck by the fact that once I actually stood in the shoes of a director and I was directing, [those] observations seemed absolutely useless."
Nichols, who says he planted the idea in the producers' minds by just showing up to production meetings, initially wasn't thrilled with the episode he was assigned. Titled "Quiet Little Voices," it focuses on the birth of Haley and Nathan's new baby, but it's filled with flashbacks rather than new material. "At first I was like, 'Oh, that sucks I can't shoot a whole episode,' but then as I started looking at the clips and trying to tie them together with my scenes, I was like, 'Wow this is really cool. Fans are going to love these,'" he says.
His favorite vintage clip involves a pivotal moment in Naley's history. "One of my favorite transitions is from Haley and Nathan's first kiss to them back in the present day," he says. "The way their heads are configured mirrors what it was like."
In addition to the Haley and Nathan flashbacks, Nichols also hints that his character, Julian, will share some pivotal scenes with Sophia Bush's Brooke. "I was really excited to have a hand in directing a very important scene for Brooke and Julian. There's a surprise in my episode. ... It's a bump in the road," he says.
That wouldn't have anything to do with the baby the couple is trying to adopt, would it? "We're making a dramatic TV show [and] things have to happen," Nichols says coyly. "[Starting a family] has been one of the biggest things in Brooke's life, and she's had a rough road. With Julian, she finally found a guy she can do that with."
Whatever the super-secret scene holds, Nichols hints that things will remain intense and emotional for his character in the season finale. "I've always been scared I wasn't [able to do] scenes like that compared to people who get to that place more easily," Nichols says. "But that day when I walked into that room, it all just happened. It didn't seem like I had to work hard to do it, it seemed like I spent three years living with this character and when you breathe that reality in so much every day it lives in you. When I walked out of that that room I left feeling like I was an actor."
One Tree Hill airs Tuesdays at 8/7c on CW.