Melinda Clarke and William Petersen

Since sultry dominatrix Lady Heather first appeared on CSI in 2001, she's been no stranger to peril. She's seen her employees and daughter murdered, and nearly got herself killed by a customer living out his morbid fantasies. Each time, Grissom (William Petersen) has come to her rescue, raising viewers' hopes that the unlikely pair — whose chemistry is strong enough to spark a brush fire — will finally stop dancing around each other and pull out the whips. But when Melinda Clarke returns on November 6, their roles are reversed. Get ready for Heather to save Grissom.

"She's in a good place now where she's made some changes in her life," Clarke says. "And we won't necessarily see Lady Heather as a dominatrix anymore."

Murders involving S&M bring Grissom back to Heather. "I think he's probably at one of the lowest points in his life — personally and professionally," Clarke says. "He comes to Lady Heather to ask for her help on a case, but she questions whether he's here for the case or because of himself. She's helping with this murder, but she says, 'You don't need me for this. Why are you really here?' "

For Clarke, who'll appear in a three-episode story arc on Eli Stone starting December 9, exploring the relationship between Heather and Grissom for the past seven years has been a dream come true. "Heather, to me, is that woman who's so evolved and so cool in her own skin — she's the female version of him."

But Petersen's departure from the show later this season may put an end to her regular appearances, at least for now. "It doesn't quite seem right to have Lady Heather there without Grissom," Clarke says. "I think they belong together because they balance each other and it's fulfilling for the audience and frustrating at the same time. This is an interesting episode because it's all about what's not said. They are true friends, but maybe he's looking for something more from her."

For executive producer Carol Mendelsohn, the Heather-Grissom chemistry has been fascinating to explore. "Lady Heather's knowledge of human behavior has always been an interesting complement to Grissom's encyclopedic knowledge of forensic science," she says. "The two characters feel at ease with each other and share an intimate respect for one another. In a different world — one without Sara Sidle in it — Lady Heather and Grissom might end up together."

So what about Sara (Jorja Fox)? Clarke hesitates to imply that her episode will answer any questions about who will walk into the sunset with Grissom. "Sara and Heather are still very much a part of his life and [the episode] is going to be very moving for the audience in so many ways," she says. "It's definitely an intimate episode."

Does she think the CSI and the dominatrix ultimately belong together? "From my point of view, sure. Why not? Lady Heather's not going anywhere." Clarke pauses. "It's just a matter of what Grissom's compelled to do." — Carita Rizzo