The Good Wife will end without Kalinda, but it certainly could not wrap up without one final appearance from everyone's favorite quirky lawyer: Elsbeth Tascioni.

"I love the role and it's been one of the greatest gifts I've had in my career. Every time they ask me back, it's like a little gift and I get something new," Carrie Preston, who won a guest acting Emmy for playing Elsbeth in 2013, tells "I'm so excited I got to do one more before the end."

The Good Wife: What to expect in the final episodes

Because of her upcoming NBC comedy Crowded, Preston was only available for one episode of The Good Wife. She'll return on Sunday (9/8c, CBS), when Eli (Alan Cumming) recruits Elsbeth to figure out why the FBI is investigating Peter (Chris Noth). Per usual, Elsbeth deploys her idiosyncratic methods to uncover the truth. "Elsbeth's pretty game to do it when [Eli] asks. She's always up for a challenge," Preston says. "It's delightful and weird and fun. Her brand of genius is shining as bright as always. You're going to learn something that definitely will help shine a light on why [the FBI is after Peter] in this episode. Elsbeth has some ideas about what might be going on, and her investigative side comes in."

Also coming into in the picture is Elsbeth's heretofore unseen ex-husband and fellow attorney Mike (Will Patton), who Preston says will illuminate Elsbeth in a new way for fans. Needless to say, theirs was not your average relationship. "There's obviously never anything that's traditional with Elsbeth," Preston says. "Their interaction is fun. You'll see maybe why they didn't work out. It might make a little bit of sense why that chemistry didn't pan out. I think she's even wondering how she can have a relationship with herself! I do."

Discovering new aspects about the mercurial attorney is why Preston loves playing her — and why she believes Elsbeth has been a fan favorite since her first appearance at the end of Season 1. "She's definitely not like the other kids. People, I think, want to see things on TV that they don't expect," Preston says. "We kind of see it all and it's kind of hard as a culture not to be cynical about stuff, so people want to have something fresh to look at that makes them go, 'Huh?'" That curiosity thoroughly piqued last season when The Good Wife went full Elsbeth, devoting a whole episode to show the inner workings of her peculiar, beautiful mind. Her acrobatic cognitive detours, complete with clowns, penguins, ice cream, xylophones and pumpkins, were basically an acid trip without the acid.

11 reasons Lucca Quinn is our new favorite Good Wife character

"Knowing exactly how her brain works now, you can use your own imagination of what images would be flying through her head [in Sunday's episode]. I certainly have some ones in my mind. That's what makes her so fun and unpredictable. ... Just when you dig in and think she's making a choice for one reason, you find out later it's for a totally different reason. You will see some of that going on in this episode," Preston says, crediting the show's underrated strength and skill at fleshing out its recurring characters. There's a specificity to each one from the get-go that begets return appearance after return appearance. "I don't think there's a single guest star that didn't have some kind of unique characteristic in their character that was rooted in something organic and real and a lot of times funny and bizarre," she adds. "I think they kind of revolutionized the lawyer show because of that. Every judge they've had was 100 percent memorable."

So memorable and beloved is Elsbeth that creators Robert and Michelle King have specifically mentioned her for a possible spin-off. Preston's current priority is Crowded, but she'd never say no to more Elsbeth.

"I'm just so honored that they would highlight my character and say, 'Yeah, we wanna see more of her,'" she says. "I'm open to anything and I certainly would love to work with them again. It could be a little bit like Columbo meets Monk. You could have something pretty interesting and smart and mysterious and kind of surprising. ... Even if this is it for me, I'd like to think that Elsbeth is going to continue on and do her thing. Elsbeth is an unlikely superhero. I certainly wish I were as half as brilliant as she is. It's delightful to get inside of her mind and see where the twists and turns take her. It's one of the most exciting roles I've ever gotten to play because of that."

The Good Wife airs Sundays at 9/8c on CBS.

(Full disclosure: is owned by CBS.)

Relive The Good Wife's best elevator moments