'NCIS' plans another flashback episode: Mark Harmon and Michael Weatherly give details On a nearly 100-degree day in Los Angeles, drought-stricken Griffith Park stands in for Baltimore in the fall. The "NCIS" cast members on hand are sweating it, since they're all wearing their agency jackets. Michael Weatherly (aka Tony DiNozzo) has it the worst, since he has to sprint up and down hills after a suspect. In the next setup, he's standing over a corpse, trying not to drip sweat on the poor actor who's playing dead. "Can a dead body get a sunburn?" he ad-libs. The line stays in. After the cameras stop, Weatherly compliments his other scene partner on his deadpan reaction. "I love it when I say that and look up at you," he tells Mark Harmon (Leroy Jethro Gibbs). Nobody does that slow burn like you. Gibbs will be absent from some of this episode, "Once a Crook" (airing Oct. 22), because much of it consists of a flashback to DiNozzo's days as a Baltimore street cop. Their characters first collided in a previous time-warp episode, "Baltimore"; the 1998 flashbacks in this installment predate that. Yet the story should shed light on the relationship these two have now and further solve the mystery of why a stoic man like Gibbs picked a cutup like DiNozzo to be his No. 1 son on the NCIS team. A few weeks later, we caught up with Harmon, Weatherly and executive producer Gary Glasberg in the much less humid writers' room. TV Guide Magazine: Fans are never more excited than when they hear "NCIS" is doing a flashback. Will this episode provide psychological insight into Tony? Weatherly: For me, the most interesting part of this episode was how I didn't realize until we were shooting the flashback scenes that Tony used to be quite earnest, focused and almost without any defense mechanisms. I'm like, "Oh, this is before. He was a movie buff, but it hadn't become [a major] part of his personality yet. Glasberg: You get to see some formative moments for Tony that got him to the point where he is now. Clearly something started to shift with his interests in law enforcement, taking it from the cop stage to the detective stage to ultimately what drew him to NCIS. Maybe there's still a piece missing that we'll get to later on. Weatherly: There's a reason Gibbs picked Tony to be in his world. We saw part of that in the "Baltimore" episode, but what this episode shows is more how these guys have a shared understanding of the job. There's a photo behind Gibbs's desk, which is actually of a character Mark played a long time ago in [the short-lived series] "240-Robert." As we were getting ready to do this episode, I was looking at this picture of Mark. I stole his haircut from "240-Robert." [To Harmon] I hope you don't mind! I didn't look quite as good as you looked back then in the tight shirt. Harmon: By the time we started doing flashbacks, which was a number of years in, we'd earned it. Certainly as an actor you have more to grip on to. It's interesting to hear Michael talk about how, when he played this guy in this episode, he learned he was earnest, traditional and calm in the heat of action - a lot like the guy who plays him. But those are choices he can make 11 years in that he couldn't have made in year one. There's still a ton of mystery to the characters, and still a lot of growth, too. TV Guide Magazine: When we interviewed Cote de Pablo about leaving the show, she said that, speaking as a fan herself, if her sudden departure created opportunities to do shocking things or create new casting opportunities, that was great. Harmon: Aw, gee, that's nice of her! [Laughs] Glasberg: This is a staff and cast that respond to being thrown something they weren't expecting. I couldn't be more enthusiastic, honestly, with where we're headed this season. I'm really excited about Emily Wickersham [who will play Bishop, an NSA intelligence analyst, starting in November]. I almost used the word reenergized. It's not that we weren't energized before, but it's good when somebody lights a fire that you weren't expecting. Weatherly: It's been an incredible experience to feel everybody lock into a newish rhythm that feels surprisingly comfortable and classic "NCIS." I'm elated by the energy that comes out of this place, and every guest star who comes through is like solid gold. TV Guide Magazine: Every possible twosome on the show carries a certain intrigue, but maybe none more so than the mentor-mentee dynamic between Gibbs and DiNozzo. Do you agree? Weatherly: It's why I come to work. The great gift of "Baltimore" was that I got to tackle Mark - given his real-life history [as a star UCLA quarterback]. Then I turned him over to cuff him and he punched me in the face! And yet it wasn't antagonistic. Those characters are both only children, I believe, and there's a loneliness to Gibbs. He's a sniper. He's somebody who's in his own world. And that's something with Tony, too. They line up a little bit, even though they're wildly, photonegatively different - you would think. Glasberg: The more years that go by, the stronger the understanding between these two fantastic actors. There are little things I pick up on in the editing room - I'll see a response that works with just a look, where maybe earlier it may have required a line. That nuance is fun for me. Weatherly: I remember the first time I ever said "Thank you" after a head slap. Which was an instinctive, unscripted moment of silliness that got a laugh in rehearsal, so it stayed in. And then, as I thought about it, I was like, "You know what? That's really true! DiNozzo is like, "Thank you for reminding me to get my head back in the game." He needs Gibbs that way. Subscribe to TV Guide Magazine now!