Stana Katic and Nathan Fillion, Castle

If Nathan Fillion is Castle's king, Stana Katic is the queen. And in recent weeks, the hit procedural comedy has turned its focus on Katic's character and her back story — mainly, her mother's murder.

See photos of the Castle cast

Katic, who plays Detective Kate Beckett, tells TVGuide.com that she enjoyed getting some resolution — she now knows the killer, but not who hired him —and promises there is more to come.

"It was really a smart way to drop more information but not fully resolving it," Katic says. "I think it is going to be a driving force as we continue to move on. They'll definitely be dealing with it — probably not in the next couple of episodes. But I'm sure before the season's end, we'll get another big bombshell regarding that story line."

More important, Katic says, was the introduction of Beckett's family life. "It was one of my favorite [episodes] because it delved a bit deeper into what is behind Beckett's reasoning for becoming a detective and it introduced us to her father," she says. "There's a really loving relationship between Beckett and her father. There's a lot of care, and he acts as a mentor and a wise, older character in her life. I think that's great because we get to see a more vulnerable side of Beckett."

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In Monday's episode (10/9c, ABC), which features a former major league baseball player's murder, Beckett reveals that her father instilled in her a love of the national pastime as a young girl. During the investigation, Beckett crosses paths with former New York Yankees and current Los Angeles Dodgers manager Joe Torre (in a cameo), and the word star-struck doesn't begin to cover her reaction.

"All of the crew was just gaga over Joe Torre being on set," Katic recalls with a laugh. "My makeup artist is a huge fan, and she could barely speak because he was in the chair next to me. She was quiet as a mouse, and it was so adorable. My character gets a great moment to get geeked-out over meeting him, and I definitely was speaking on behalf of the entire crew in that moment."

But while Beckett shares the excitement with her pops, Castle struggles with his feelings about not knowing who his father is. Katic says she hopes the show allows Beckett to help Castle work through those issues.

"I think that's an important relationship, and I think Castle might throw it off to protect himself," she says. "But I'm sure it's valuable for him to know who [his father] is and to have some kind of connection with that person. I'm sure it will come up again, and I think it's an interesting character discovery for everybody."

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Katic says it's been fun to show so much of Beckett's softer side. But she says Beckett won't ever fully lose her edge. "When Beckett's in the work force and she's catching killers, she has to be the point of the spear," Katic says. "She has to be unwavering and strong. When we allow the character to be shown in her private moments, that's a different side, a different paradigm."

And how does the push-pull tension with Castle figure into that paradigm? Not only has Beckett pretty much accepted that Castle is a valuable resource on her team, she even blew off a date with the FDNY calendar's Mr. July for a cheeseburger with Castle.

"Beckett and Castle will continue to get their flirt on for sure," Katic says. "They'll go and enjoy dates with other people for a while and see how that affects the other character. The two of them are very well-suited for each other, so, of course, they're always doing that dance with the devil."