Ophelia Lovibond, Lucy Liu and Jonny Lee Miller Ophelia Lovibond, Lucy Liu and Jonny Lee Miller

Winter is coming... Kitty Winter that is.

When Elementary returns for its third season on Thursday (10/9c, CBS), Joan Watson (Lucy Liu) will give Sherlock Holmes (Jonny Lee Miller) a rather chilly reception when he returns to New York. After all, he abruptly ended their crime-solving partnership when he hared off to England to work for MI6. Even worse, he replaced her with a newer, younger model: Kitty Winter (Ophelia Lovibond), Sherlock's new protégé.

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"Joan's not really thrilled about Kitty," Liu tells TVGuide.com. "That's not a good feeling, to think that you are not a unique and special person when they had a special relationship. It immediately degrades everything that they've been doing, like, 'Oh, we're going to do the same thing. I'm going to train somebody else to do that.'"This feeling of betrayal further alienates the two former partners, who haven't been in touch for the eight months that Sherlock's been gone. In that time, so much has changed. Not only has Joan been working solo as a consultant for the NYPD, but she also has a new man (Smash

's Raza Jaffrey) in her life. "She's grown more confident in how she manages a case on her own," Liu says. "In separating from Sherlock, she's now developed a relationship with someone else. It's a relationship that's fairly new and gives her a nice balance. It hasn't had Sherlock around when she met [her boyfriend] and during the relationship, so it will be interesting to see how it works if they ever meet."Despite appearances, Sherlock may not have moved on with his life as successfully as Joan has. "He's actually quite a bit upset that he doesn't get more of a welcoming reaction," Miller says. "He's actually back because he misses Joan and misses that dynamic and misses their work together. His great excuse is that circumstances have brought him back, but he's very, very happy about it but doesn't want to show it. He is trying to pretend to a certain extent that he wants to be a mentor to somebody else. I think he's sort of covering up his own frustrations."Unfortunately, Liu says that "the dynamic is not the same as it was before when she sort of followed him around" since both now act as independent consultants to the NYPD. And while Sherlock's new apprentice is the one following his lead, she's doesn't have the warm relationship with him that Joan had."They don't know each other," Miller explains. "He's training her and is really quite firm and not particularly pleasant to her. He's probably trying to boss her around, dominate her a bit more as far as the teacher and mentor kind of thing goes, [more] than he ever would be able to get away with Joan Watson. So he's sort of taking advantage a little bit."

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Lovibond says, "Kitty is more volatile when she's told to do something. She doesn't like it. She questions why and she has to be given a reason; she won't just do it. It's like he wants to get the better of her in that, whereas Joan is just more evenhanded in everything. But Kitty wants to learn, she wants to be better, so she does what she's told even though it really grates on her. She is very independent."That friction extends to how she gets along with Joan, whom she sees Sherlock regarding as a true partner. "Kitty begins to realize Joan is a threat in the sense that she has done this, she's played this part before. That's always a little bit intimidating," co-executive producer and director John Polson says. "In the first episode, Kitty is wondering, 'Am I going to be out because Joan and [Sherlock], they seem to be connecting again? She's around and doing the same case.'" And while their interactions don't get off to the best start (watch the preview below to see how they literally come to blows), there's hope for Sherlock's two students. "Joan may want to be in Sherlock's life but not necessarily back the way it was before. And therefore, she's no direct threat," Polson says. "She's a very empathetic human being. She's got her history as a doctor. She clearly is who she is. So I think what happens is that Kitty settles down a little bit and starts to trust her a little bit more."But who exactly is Kitty? It remains to be seen if she's deserving of the responsibility that Sherlock has placed in her. "She's hungry for something. You can see that," Liu says. "I think from Watson's point of view, she's kind of got her head a little bit tilted, like, 'What's up with her? Something's not quite right with her.'"Elementary kicks off Season 3 on Thursday at 10/9c on CBS. Check out a preview of the premiere below and an exclusive first look at the Season 3 poster:

(Full disclosure: TVGuide.com is owned by CBS.)Additional reporting by Sadie Gennis