Cote de Pablo, Michael Weatherly, Perrey Reeves Cote de Pablo, Michael Weatherly, Perrey Reeves

Much like his character on NCIS, Michael Weatherly has a tough time taking things seriously.

So when asked about the arrival Tony DiNozzo's ex-fiancée Wendy (Perrey Reeves) on Tuesday's episode (8/7c, CBS), Weatherly can't help but crack wise. "I like to think they named her Wendy because DiNozzo is Peter Pan," he tells

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Joking aside, the episode — which finds DiNozzo & Co. investigating the death of a Navy captain with ties to a secret society of superheroes — is actually part of a much larger and serious Season 9 arc for Tony."We went into [this season] with the sense of talking about decisions in the team members' lives," executive producer Gary Glaberg

says. "It affected the story I wanted to do for [Episode] 200, and there have been elements of things Tony has been reflecting on all season, which is really why we wanted to do a story with Wendy. It really provides some more insight. ... I'd like to believe that this arc that we've set up for Tony over this season has been enlightening for everybody so we can sort of see what moved him from the frat boy that he was to becoming the special agent that he is now."Reeves agrees with Glasberg's assessment. In particular, she says the way things ended between Tony and Wendy, who is now an investigative journalist looking for details on Tony's case, provides answers to why Tony is such a jokester. "It sheds some new light on his character," she says. "He was brokenhearted, and I think he sort of protected himself all this time. ... In this episode you see the soft side. He's super funny, but I think when you see the two of them interact, you realize that some of it is a little bit of a protective device."

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But make no mistake: This duo still has feelings for one another. "It was the most important relationship that he had," Weatherly says. "And we will find out how that engagement ended. Who left whom? Was it Wendy or was it Peter Pan that flew out the window?" Adds Reeves: "Wendy carries a huge flame for Tony. I think she was afraid [back then]. I think she has been hurt in her past, and here was this person who brought out all these qualities in her and as much as she wanted to go down that road with him, she was too wounded."So will Wendy make a play for Tony all these years later? "She realizes that we're only on this planet for [so] few days really in the end," Reeves says. "And she has nothing to do but to tell the person that she really, really loves that she really loves him."All this portends very bad news for those fans who long for Tony to hook up with his fellow agent Ziva (Cote de Pablo). And Reeves is ready for the backlash. "I'm anticipating it," she says with a laugh. "I've got like a big, huge storage unit right outside of my house. I'll use it to put the letters in because I think there's going to be a lot of hate mail."

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But Perrey urges viewers to watch the episode before committing to a letter-writing campaign. "Wendy really likes Ziva," she says. "As women, we're very sensitive to the energies of things that are going on, and I think that Wendy can feel and see that there is something there."In fact, Wendy may just push Tony and Ziva a little closer together. "She's actually encouraging Tony to not be afraid," Reeves says. "She doesn't say it in so many words directly, but she's basically saying if there's someone out there, you need to let them know because life is too short."Will the advice stick? "I do think that all of this is leading up to something," Weatherly says. "This season, there's been a real maturity to Ziva and Tony and how they are with each other. It's all having a cumulative effect on him and that changes the nature of his relationships with the people he works with."Adds Glasberg: "I think by the end of this season,[Tony and Ziva] are both going to have a better idea of what they want for the future, and that may influence how they interact with each other."NCIS airs Tuesdays at 8/7c on CBS.