David Duchovny

Californication faces a dilemma in Season 4.

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The Showtime comedy, which returns Sunday at 9/8c, ended its madcap third season with a gut punch: Hank (David Duchovny) was arrested on assault charges moments after telling his ex, Karen (Natasha McElhone), of his tryst with Mia (Madeline Zima), who, unbeknownst to Hank at the time, was underage. And while that reveal presents plenty of drama for Season 4, it also unearthed a crucial secret that's carried the show since the pilot.

"We've been using that event as a motor for behavior and plot since the beginning," Duchovny tells TVGuide.com. "And I guess that now that is no longer a secret, it is no longer a motor. In a way we're free of it, which will be interesting for the next year, and we'll have to come up with new stuff."

But before that happens, the show definitely seems to be reflecting on its past. Creator and executive producer Tom Kapinos says that was completely by design. "The ending of last year allowed me to put Hank back to the way he was at the beginning of the show, kind of a down-and-out Hank who has to deal with pretty much everyone hating him," he says. "There's sort of nowhere to go but up."

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As the season begins, Karen won't talk to Hank. Ditto Becca (Madeleine Martin), the couple's teenage daughter. "That's probably the most painful thing for Hank," Duchovny says. "Becca is growing up to the point where she's going to judge him as a person and not just as a father and decide that for her own well-being she's got to create some distance. This year more than ever, she's started to make harsher judgments on her father's behavior, and I think Hank does begin to take that into account more than anything else really. It is painful for him."

So Hank turns to best friend/agent Charlie (Evan Handler) for help finding a job and hotshot attorney Abby Rhodes (guest star Carla Gugino) for help in the courtroom. Charlie lands a deal for Hank to rewrite the script for the adaptation of his novel about his indiscretion with Mia, starring lunatic Hollywood fixture Eddie Nero (guest star Rob Lowe) as Hank. Abby and Hank, meanwhile, end up discussing legal strategy beneath the sheets.

Kapinos says Hank and Abby's relationship has more weight than his flings in the past. "The design was to basically come up with a character who could rival Karen," he says. "She is someone who might give us another way to go."

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Also getting an alternative romantic partner is Karen, who begins to fall for the father (guest star Michael Ealy) of one of Becca's bandmates (Zoe Kravitz). "The goal for the season was to get Hank and Karen to a place where they could kind of let each other go in a way that was bittersweet but not depressing," Kapinos says. "I wanted to see her finally have chemistry with someone else and ... see what that brought out in Hank. I wanted him to see that there were alternatives out there, and that maybe this was just a fool's quest to keep chasing down the same relationship for years and years."

However, Duchovny believes that the back-and-forth between Karen and Hank will always remain the heart of the show. "Hank and Karen have a love for the ages," he says. "Whatever it is you believe with respect to love and how much someone should 'take' before they walk out the door... that is really what the show is about. Unlike the festering rape charge or the relationship with Mia or whatever love interests come and go for either Hank or Karen, their relationship does not get resolved until we resolve the show."

Which brings us back to the dilemma: With so much of the show's history revealed and dealt with, is now the time to call it quits?

"Each season has been kind of a chapter, and this closes the door on the Mia stuff, and there's no going back to it," Kapinos says. "So it's about how you begin again. I don't think it's the end, but I do think it's time to shake it up a little. People toss around the word reboot, and I don't know if I believe in that for this show. But we dealt with all the stuff we set up in the first episode, and so it's time for it to evolve and move in a slightly different direction."