Melina Kanakaredes, <i>CSI: NY</i> Melina Kanakaredes, CSI: NY

The television landscape is full of tough female cops, and Wednesday's episode of CSI: NY proves that Detective Stella Bonasera (Melina Kanakaredes) deserves to be counted among the toughest.

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"We're always in danger, but Stella has this bizarre empowerment," Kanakaredes tells "She almost died in Season 2 by someone she cared about. Now, she's fearless about life-or-death situations. It's like Rambo Stella."In Wednesday's episode (10/9c, CBS), Kanakaredes and her character will have to live up to that moniker. "Literally, I am getting my head bashed in at the bottom of a pool by this bad guy," Kanakaredes says of some of the episode's more perilous moments for Stella. "I flip over in a car and I'm upside-down. I'm very proud; I did all my own stunts. I pinched a nerve hanging upside-down in a harness. It was one of those moments where I was like, 'I am not acting here.'"But the episode is not all about Stella's hard edge. The story revolves around Marina Garito (Moran Atias

), a woman whose twin brother was killed when they were kids. Garito formed a bond with Stella years later, and calls in weekly to see if there's been any cracks in the otherwise cold case. But just when Garito makes a breakthrough, she winds up dead of an apparent suicide.

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"Stella's been taking these calls for four years, and she just doesn't believe it's a suicide," Kanakaredes says. "It becomes this wonderful true-to-life story [of] guilt and obsession for Stella. She takes on the obsession of this young woman who needs answers, except she's parlaying it to find out what happened to this girl. And she's haunted — literally haunted."Fortunately, Stella is able to lean on Mac (Gary Sinise) and the other members of her team, including Flack (Eddie Cahill). "I think she knows the reality," Kanakaredes says. "There's a great scene between her and Flack and he's like, 'We all have these people that call us every week, and you can't beat yourself up.'"Still, Stella is on her own when it comes time to make her case. "She just won't believe it," Kanakaredes says. "That's pure gut instinct and that's pure Stella. She doesn't care what the evidence says, and that's what I love about the character: She is so not black and white. She is able to cross lines and come back over and say, 'See, I crossed the line for this, but I was right.'"