Apart from "Mad Men" in its 1960s setting, most TV dramas shy from showing anyone with cigarettes.

But that doesn't mean Kalinda Sharma isn't constantly smoking on "The Good Wife." No cigarettes are involved, mind you, nor are they needed by this steamy in-house investigator at the Chicago law firm of Lockhart Gardner. With her implacable shrewdness, sass and sexuality, Kalinda heats up every scene she's in.

No wonder she has emerged as a viewer favorite among the many colorful characters populating this CBS drama. And no wonder Archie Panjabi, who last year won an Emmy for her portrayal of Kalinda, can hold her own in a robust cast of actors who include series star Julianna Margulies as well as Christine Baranski, Josh Charles, Matt Czuchry, Alan Cumming and Chris Noth. ("The Good Wife" airs Sundays at 9 p.m. on WCSC.)

"I'm not just a woman in a pair of boots," says Panjabi, describing her character with delicious understatement.

Along with her trademark knee-high boots, Kalinda is distinguished by her defiant composure -- little if anything throws her, stops her (including ethics or legal niceties), or penetrates her well-defended shell.

Adding to the intrigue of Kalinda is her matter-of-fact bisexuality, and her exotic but so-far-unexamined ethnic origins. To its credit, "The Good Wife" makes nothing of the fact that the actress chosen to play her is Indian and, though British-born, has adopted for Kalinda a throaty, Americanized purr that obscures any regional identity.

In short, Kalinda cannot be categorized. She is who she is: a source of fascination.

"I think that's the way forward," says Panjabi. "You don't focus on the differences, you don't make an issue of them -- you just present them."

Meanwhile, the enigmatic Kalinda will have a few more layers peeled away in coming episodes.

"I've looked at the script and gone, 'Oh, my God. Really? Is "The Good Wife" going to go here?' And they went there," she teases. "Playing Kalinda definitely keeps me on my feet."

The 39-year-old Panjabi knew from a tender age that she wanted to be an actress, "and I said no one would stop me from doing it.

"Coming from an Indian family and seeing the differences between them and our English neighbors, the differences in cultures always fascinated me," she says. "That's probably the source of my desire to earn a living out of being different people. There's nothing more challenging or exciting than being able to get into the heart and soul of another human being, and show that to the audience convincingly, from head to toe."

She landed roles on British television and made her film debut as a soccer-loving tomboy in the romantic comedy "East is East." Subsequent films include "Traitor," "Bend It Like Beckham," "The Constant Gardener," "A Good Year" and "A Mighty Heart."

Along the way she wed Rajesh Nihalani, a tailor with whom she lives in London when professional pursuits aren't intruding.

But three seasons ago, she was invited to be part of a prospective New York-based TV series, a blend of courtroom procedural, high-stakes office battleground and domestic melodrama.

"At first, the role kind of scared me," she concedes. "Kalinda seemed like somebody who used her looks as opposed to her mind, and I was nervous that she would have a limited range. But then they also made her incredibly smart."