'Smallville's' Cassidy Freeman on what 'Luthor' means to Tess

"I was really excited about the whole thing,"  said Freeman. "It it really gives her character more depth. Up to this point, Tess has sort of been an amalgamation of other characters. She's a little bit mysterious, so she's a reflection of what everyone thinks of her. This [reveal] gives her a place in the story."

Friday's (Dec. 3) episode, "Luthor," is sure to add more new twists to the family legacy. Tess finds a Kryptonian box that once belonged to Lionel (special guest star John Glover). But when Clark activates the box, he's transported to an alternate universe where the Kents never found him and he was raised instead by Lionel, as Clark Luthor.

While Clark tries to get home, he has to pretend to be his murderous alter-ego -- and as he encounters his friends in the alternate universe he realizes the impact one small change could have had on his life.

Throughout the episode, we'll also see Clark Luthor in the Smallville we know and love. "You'll see both worlds going at the same time," Cassidy says."It was a bit of dual personality that week for all of us. But [executive producer] Kelly Souders was directing, and she'd obviously been with the idea from the inception, so she was so versed in who these alternate characters were that it made the transitions easy."

Freeman says that with the writers and producers based in LA and the show's set in Vancouver, the cast's interactions with the writers and producers are usually via videoconference. "Kelly came in so ready to learn," she says. "But we really learned from her too. She was totally solid in terms of how she wanted things to look and the different atmosphere."

The CW has released some teaser clips from "Luthor," including scenes that display a whole new dynamic between Clark and Tess. "Our characters become textbook week-to-week, so any chance we have to take them and flip them and play something really different is great," Freeman says. "Especially with an actor you're so comfortable with, the way Tom and I are. We had a really great time exploring the different versions of Clark and Tess and how they'd react to each other."

Of course, the episode presented the opportunity for Freeman to work with actors she may not be as familiar with as well. Since she was added to the cast in 2008, she's had her fingers crossed to work with the actors who made the Luthors so appealingly devious.

"John Glover is awesome," she says enthusiastically of the returning star. "It's been a total dream of mine to work with him from the time I started the show. I've been wondering how they could bring him back in a way that would let me interact with him, and man, they did it so creatively. It was really fun. He's so talented and just brilliant to work with." She pauses. "I do still really want to work with Michael Rosenbaum, though. Just to throw that out there."

In the meantime, though, she has plenty of ground to explore with Tess. "Now that she knows she's a Luthor, some major questions are answered for her. She's got this sordid past that's now explained a bit, but it's also very upsetting in a way. It's like now, any evil thoughts or evil doings aren't just circumstantial. They might be ingrained in her; they might be in her blood."

Her connection with the Lex clone she's essentially nurtured may grow deeper as well. "Internally, knowing that she's a Luthor definitely changes that connection," Freeman says."It's not just a sort of mothering instinct, it's an actual biological connection to this person."

As powerful as the Luthor name is for Tess, it may have an even deeper resonance for Clark and Oliver, and though Tess is currently trying to keep her true identity a secret, Freeman confesses, "It's just like any secret in 'Smallville.' It's a secret until it can't be a secret anymore."

How will our trusty superheroes react when they hear that Tess, who they finally have accepted as part of their team, has Luthor blood in her veins?

"They'll have a choice -- if and when they find out," Freeman says coyly. "They can accept her for it and base their judgment on her actions, or they can totally not accept it and push her away. Knowing the characters, I'd imagine that Oliver will probably have a much harder time accepting it than Clark will. Clark always wants to see the good in people."

We haven't seen much of Tess's relationship with Lois this season, but Freeman assures us that the two will share more scenes moving forward. "Their relationship is more collaborative, now that everyone knows what's going on and Clark's secret is out," says Freeman. "They're all on the same team now, and they can really look at the bigger picture."

Chloe (Allison Mack) returns in Episode 12, but don't expect to see much interaction between her and Tess for her first few episodes back. "Allison is back, yes, but we haven't had any scenes together, to be honest," Freeman says. "She's got a lot of other storylines to take care of. In terms of Tess running the Watch Tower, I think that Chloe made this really strong decision to leave, and she understands the repercussions. She'd rather know things have been running smoothly than worry about having been replaced somehow. She's a strong character that way."

As this is the final season of "Smallville," Freeman admits that there's the occasional bittersweet feeling on set. "There are little moments of sadness," she says. "When we finished Episode 11, we all sort of looked at each other and thought, 'Well, we're halfway through.' But there's also a sense of excitement in terms of moving on and exploring new things next year."

Freeman's post-"Smallville" plans? "I have a plan to maybe sleep for a week," she laughs. "That's as far as my plans go right now."

When it comes to whether Tess will continue on the straight and narrow path or go with her Luthor heritage and take a dark turn, Freeman insists she doesn't know what the writers' plan is.

Now, though, she's changed her tune a bit. "The writers have two distinct avenues they can take now, with Tess," she says. "Yes, as an actor, it's fun to play dark and evil. But I've gotten to know Tess now, I've gotten to be close to the character, and honestly, I want her to do good and to be happy. I think there's a way to do that and still thrive creatively."