Kirsten Vangness Kirsten Vangness

After seven seasons, Kirsten Vangsness will finally don a Kevlar vest on Criminal Minds — and just like Garcia's colorful personality, the vest is one of a kind.

Check out photos from Criminal Minds

"I was so excited when they told me. They made that one especially for me, which was very nice," Vangsness tells "The seamstress came in, like, 'We're going to make another dart in this.' In actual Kevlar vests, they don't have darts. But they put them in mine. It's very flattering. [The other cast members' Kevlars] are fitted to them too, but mine was totally hugged to my curves. It's a girly Kevlar — perfect for Garcia!"The fact that Garcia is wearing a Kevlar means one thing: She's going into the field. Although the tech goddess has traveled with the BAU before — and lest we forget, got shot — she has never been out with the team in the pursuit of an unsub. That changes Wednesday (9/8c, CBS) when a case turns personal after her friend, Monica (Brigid Brannagh

), from her survivors' support group, disappears seven years after her daughter went missing.In the past, Garcia's emotions would typically take over in such intense circumstances, but she manages to keep it all under control this time — even insisting on going out in the field. "We really had to make sense of why she's doing this. Like we know she's the big empath and the one who wears her heart on her sleeve. How could she do this? But the thing that helps them is that she uses her emotions to help solve that case," Vangsness says. "She knows her friend will die unless they get this guy, so she's going to steel herself and actually use that emotional power to her advantage because the stakes are so high. She has no choice but to step up to the plate."

Criminal Minds' Joe Mantegna: Rossi's ex-wife's visit is bittersweet

Plot aside, Vangsness was thrilled to get in on the unsub-tailing action since it meant she got to work with the rest of the cast instead of being exclusively held up in her office, where her primary co-star is a green screen. "I know them and love them and we all hang out together, but that's a major part of their day — them being in their FBI vests with their guns out," she says. "We have this guy ... who tells us how to hold the gun and makes sure everything is accurate, so it was very strange when we stormed the evil castle sort to speak and he was like, 'You have to hold on to the back of A.J. [Cook] and then you do this.' I'm not used to that."She's also not used to being at the center of the episode's climactic scene. Luckily, the outdoor scene allowed her to prep just fine — with a stick. "I wasn't like, 'Oh my God! I have to cry and scream.' I found a stick outside and I started hitting things with it, which I found hilarious," Vangsness says. "Walking around and just hitting trees — hilarious and fantastically entertaining to me! Then they'd be like, 'OK, we're ready to shoot.' I walk over and then I'm in tears. It was the strangest thing, but I think I needed to do that or else I would've walked around all day like a basket case. If I teach an acting class, I'd be like, 'Find a stick...'"The stick was so helpful that it now has a permanent home among the tchotchkes on Garcia's desk (despite the prop department's best efforts to remove it). But Vangsness doesn't want to add any more "out in the field" memorabilia to the collection. Despite this venture and Garcia taking over case presentation duties for JJ (Cook), Vangsness hopes Garcia remains chiefly behind her wall of computers.

Exclusive: Criminal Minds books Charles S. Dutton

"I like it when I get to go away with them, but she would never go in the field all the time and she would never, never become a profiler. She is somebody to profile," Vangsness says. "She's so about the triumph of the human spirit under any and all conditions that I think that that would just be really counterintuitive. They've said to me, 'It'd be great if we gave Garcia a gun.' She would never! She doesn't believe in guns. You can maybe give her a taser. A lasso — she might be able to rock a lasso. A crossbow, maybe — something you've got a decent chance of living through. There you go, next time we'll see her with a crossbow!"