“Abby is in Mexico simply to teach, but she does make some cold-case discoveries while she’s there,” Perrette tells TVGuide.com. “She makes a few discoveries, actually, that come back around to other parts of our NCIS story lines that have been building for years.”

In particular, Abby finds a bullet she believes she can trace, which makes Gibbs, who murdered a Mexican drug dealer responsible for the death of his wife and daughter, more than a little nervous. The discovery will greatly impact Gibbs and Abby’s relationship well into next season.

“We’re really getting into their relationship, and it’s heavy,” Perrette says. “There’s a lot of stuff going on. We’re going to new territory and putting a microscope on the intensity of their relationship”

Abby’s relationship with McGee (Sean Murray) will also be explored while she’s south of the border. When McGee ends up in Mexico as well, he’s a bit jealous that Abby has a crush on the organizer of the symposium, Perrette says.

“There’s a handsome Latino stranger that Abby has her eye on,” she says, noting that McGabby fans shouldn’t give up hope. “There will always be something between McGee and Abby. They love each other and they had a relationship — clearly they went out and then they broke up. I love that the show didn’t deal with that as a contentious relationship. They may not be a couple, but they do love and respect each other.”

Perrette describes the final episodes of the season as a puzzle and says that viewers won’t want to be missing pieces. “Things are being brought up and coming together that have been being set up for seven years,” she says. “Seven years of details and memories and random stuff is coming together, which is fascinating. For our super fans who have been around since the beginning, it’s going to be, like, ‘Whoa!’”

As for that ending, Perrette says it’s being kept under lock and key. In fact, she says she shot some infamous “red-page scenes,” which include script pages that only the relevant cast members receive. After the scene is shot, the script is shredded.

“I’ve heard that there are other cast members who have had red-page scenes that I’ve never seen,” Perrette says. “I don’t even know what the final scene of the final episode is. But I’ve heard it’s crazy. I’m on the edge of my seat too.”