Marg Helgenberger, CSI

William Petersen's exit from CSI last season had many effects on the show, including the ascension of Marg Helgenberger's Catherine Willows to the role of supervisor.

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So how is Catherine doing with her new responsibility when the show returns for its 10th season (Thursday at 9/8c, CBS)? Pretty well! "The pressure's on her; she's just having to prove herself a little bit. And she does," Helgenberger tells TVGuide.com. "Catherine's a very confident person. And even though she might feel a little bit of reservation and insecurity because she's being scrutinized through a microscope, her skill and intelligence win in the end."

But she won't have to do everything alone: Nick (George Eads) is promoted to Catherine's No. 2 guy. "It takes some of the pressure off of Catherine. It's a big job to run everything and have the buck stop with her," Helgenberger says. "She promotes him because she has complete and ultimate trust and faith in Nick and his capabilities. She wants someone to bounce ideas off of, in addition to him lending her a hand."

Also lending a hand is the returning Sara Sidle (Jorja Fox), who drops in to relieve Catherine's shorthanded staff. Helgenberger says the character, who is newly married(!), is a great deal happier than when we last saw her.

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"When Sara left CSI, she'd had it and couldn't take it anymore. She needed a big break," Helgenberger says. "She's in a much better place now."

Of course, everything isn't a cakewalk for Catherine. Helgenberger says in the season opener there is "definitely some friction" between team members, but none of it is with newcomer Dr. Raymond Langston (Laurence Fishburne).

"Catherine's relationship hasn't really changed that much with him," Helgenberger says. "They're definitely more on equal footing, and I think, because they brought him in as an underling even though he's overqualified for the job, Catherine didn't know what to make of him. But I think they're on the same page; their minds work alike."

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With so much of her attention going into her work, will Catherine find time for a man? "Every year I say that to the writers and producers, and it never really comes to fruition," Helgenberger says with a laugh. "I'm hoping that changes this season. They've got it in their heads to really shy away from any grain of a person's personal life, especially when it comes to romance. I think they're just very reluctant to go down the road of veering into a soap opera."

Despite all the casting changes of late, Helgenberger says the show remains as strong as ever. She calls the opening moments of the Season 10 premiere, which was filmed using a stop-motion camera, "riveting." The rest of the episode finds the team investigating the death of a young actress who dies in a car accident that may have been no accident at all.

"They're throwing out some strong cases, some strong stories," Helgenberger says. "The quality has remained the same. It's remained as high as it's always been, if not better."

That doesn't mean that she, like millions of fans, wouldn't love a return visit from Grissom.  Helgenberger says she foresees a return of some sort, but patience is in order. "I think they really want to establish Laurence's character and not have Gil come back too soon," she says. "I don't think it will be anytime too soon, maybe toward the latter part of this year."