WARNING: “Californication” fans who have not watched the series finale should stop reading. This interview with star David Duchovny contains spoilers about that episode.

After seven seasons of charting the booze-soaked escapades of writer-cum-lothario Hank Moody (David Duchovny in a role he was born to play), Showtime’s Emmy Award-winning series “Californication” comes to its fruitful end, awash in the sunny promises of happily-ever-after and the power of the epistolary proclamation of love.

Hank and Karen are back together. Again. At least for now.

Surrounded by passengers on a plane bound for New York, as it readies for take-off, Hank declares his undying love for the beautiful and neurotic Karen (Natascha McElhone), his heart, his soul mate, the woman with whom he’s been enmeshed in an oft-maddening dance of ‘Will they? /Won’t they?’ since episode one.

“Our time in the sun has been a thing of absolute fucking beauty,” Hank reads aloud from the letter he penned. “The nightmares, the hangovers, the fucking and the punching, the gorgeous shimmering insanity of this city of ours, where, for years, I woke up, fucked up, said I was sorry, passed out and did it all over again. As a writer, I’m a sucker for happy endings. The guy gets the girls, she saves him from himself, fade to fucking black. As a guy who loves a girl I realize there’s no such thing. There’s no sunset. There’s just now, and there’s just the two of us.”

Swoon. Cue “Rocket Man” by Elton John. Credits roll.

“I’m just glad they didn’t make me memorize that speech,” Duchovny quips in an interview when asked about pulling off that final scene, a culmination of everything we’ve been hoping would happen for these two star-crossed Venetians (California, that is).

But words have always been Hank’s strong suit, and Karen has served as his muse from the moment they met. “She said one thing. I said another. Next thing I knew, I wanted to spend the rest of my life in the middle of that conversation,” Hank says of Karen early on in season 2. But can Hank remain faithful (and creatively fulfilled) should they wind up spending their entire lives together?

Per Duchovny, the answer is a resounding yes.

“I never saw that at all as even a question,” the actor proclaims. “I’m not sure you can find any time in the show when Hank was with Karen that he was with somebody else. If you look at the history of the show, what split them up in the beginning was [that] Karen went off with Bill. Karen had an affair and that kind of sent Hank into whatever alcoholic and discriminate hooking up that he did and [that] became the hallmark of the show. But whenever Hank and Karen were on, Hank did not fool around. Because of the name of the show and because of certain kind of focus on T & A, sometimes that kind of overloads the true nature of the character. The way I saw him was that if Karen’s not available it doesn’t matter who he’s with. Hank has been faithful in spurts, when they’ve been together, so I don’t see any reason that he wouldn’t be able to do it again.”

It’s true that no matter what the circumstance, Hank and Karen are always under each other’s skin. Even in the series’ pilot, in which Karen decides to run off and marry the boring-but-dependable Bill, she and Hank are so obviously meant-to-be. And while their complicated relationship weathers as many twists and turns as Coney Island’s rickety Cyclone roller coaster, Hank’s ardent, bone-deep affection for Karen — despite the drinking and sexual dalliances with a smorgasbord of nymphets, cougars and MILFs – has always remained steadfast and secure. He’s never not loved her.

Because that’s who Hank is. He is a romantic, a dreamer, a Don Quixote with a beat-up Porsche and a bevy of lyrical zingers, inspired by everything from Warren Zevon to Robert Frost, at his quick disposal (“That was not sex. That was naked poetry.”)

“One of the things that attracted me to the role in the beginning was that this would be a hyper-articulate comedy and I thought, well, I’d like to give that a shot,” says Duchovny of his choice to tackle the project. “Sometimes it feels like a lot, but [creator] Tom Kapinos was never one for things to be word perfect. Once I had the rhythm then I could exchange words here and there; it didn’t really matter whatever came out of my mouth. Tom was really liberal and not precious with his words. [Hank] is this totally unedited person. We all just had a lot of freedom to make it as naturalistic as we could.”

Likewise, Hank is a gifted storyteller, comfortable with fantasy but not so much with real life. (“He’s a functioning alcoholic, I guess,” says Duchovny. “He went to rehab, and that didn’t go so well. He didn’t seem to buy into the whole recovery lingo.”) He has spent these past seven years angling to define his artistic voice (from Great American Novelist to reluctant TV staff writer), battling writer’s block; lusting after Karen, and engaging in ribald shenanigans with best friend/agent Charlie Runkle (Evan Handler) and on-and-off again wife Marcy (Pamela Adlon). He’s been in prison, on probation and on tour with a megalomaniac coked-up rock star with whom he’s penning a doomed-to-fail musical—all while enduring the dizzying pangs of parenthood.

It’s been a heady quest.

Throughout it all, it’s been Becca, his fiercely independent daughter—slash—precocious emotional foil (played to tonal perfection by Madeleine Martin), that has kept Hank in check.

“I really thought it I was the emotional anchor of the show,” says Duchovny of their father-daughter kinship. “Not only between those two but also when you factored Mom in, when you factored Karen in, that to me that was the heart of the show. It gave balance to all the other craziness and kept it from floating away into ridiculous escapades.”

This final season, with Becca off at college on the opposite coast, Kapinos added another Moody offspring to the mix in the form of son Levon (Oliver Cooper), a slovenly 20-something misfit that Hank never knew existed until Levon’s mother, Julia, (a spot-on Heather Graham), an old flame of Hank’s, moves them back to L.A.

Levon is a jobless, video game-playing, pot-smoking virgin, a Jonah Hill-type before Jonah Hill did “Moneyball.” He’s pushy, demanding and requires non-stop attention. He’s an overgrown baby, socially incompetent and in desperate need of a dad just like Hank.

“I thought it was a good idea [to add Levon’s character] when Tom first told me about it because I really missed the dynamic of Becca and Hank,” says Duchovny, “and Oliver kind of stepped into a spot where I think we like to be on the show, where Hank is asked to be a parent of some kind or is asked to love someone in a way. I thought that was very clever. It also definitely changed the dynamic between him and Becca when she came back.”

It could be said, in fact, that it’s the collective influence of Levon and Becca that pushes Hank to surrender all trappings of youth (the Porsche, the flings) and become the person that Karen, the more practical of the two, has always wanted—and needed—for him to be. If Becca were not getting married in New York, the reason that Karen was heading there, Hank might never have gotten on that plane.

“At the end of the day, it’s all about her. It’s always been about her,” Hank says of Becca in season 2. Later, it became about Levon, too. Fatherhood is where Hank is at his most selfless, his most loving, and his most consistent.

Wherever Hank and Karen wind up, Duchovny is now moving onto other big- and small screen fare, including Anthony Fabian’s “Louder than Words,” a drama about grieving parents who build a hospital in their deceased daughter’s honor and “Aquarius,” a new NBC cop drama set in the late 1960s when The Summer of Love gave way to Altamont and the Charles Manson murders.

“It’s about the dark side of flower power, about an America that’s being dragged kicking and screaming into a new age,” says Duchovny, who plays an aging homicide detective in the series.

But he will no doubt wax nostalgic for the days when he was Hank Moody.

“I’ll miss so much about that show,” says Duchovny. “First of all, I’m going to miss working with the people I got to work with. I honestly looked forward to going to work every day and that’s not just the actors, that was the crew, that was everybody. And that never happens. When you’re trying to make a comedy it’s not easy —  it’s probably harder than making a drama — but it is fun. Because you’re trying to make people laugh and you’re trying to find what’s funny and what’s real. And I find that that’s a fun discovery process. To try and make it real, to try and make it funny, and I love doing that.”