PITTSBURGH -- What began as a takeoff of "The O.C." has, in four short years, morphed into a phenomenon no one could have predicted -- from "Laguna Beach" to "The Hills" of Los Angeles to "The City" of New York.

As "The Hills" continues its fourth season, though, Audrina Patridge isn't focused on where the show began, but on how it will end.

(Will it be with a "Hills" movie? Find out what Patridge thinks about the possibility on the MTV Movies Blog.)

Unfortunately, there are no easy answers, Patridge indicated, telling MTV News that the future of "The Hills" remains mysterious.

"I don't know," Patridge said from the set of "Sorority Row," a new horror film she's co-starring in with Rumer Willis and Briana Evigan. "I mean, we're still filming the fourth season till December, and then ... who knows if there's gonna be a fifth season or if there's an end?"

The 23-year-old up-and-comer is trying to begin a film career with roles in the aforementioned "Sorority Row" and "Into the Blue 2." Series co-stars Lauren Conrad and Heidi Montag are similarly moving on to other pursuits.

In the end, that might be the nail in the coffin for the series as a whole, Patridge said.

"I feel at this point, we all kind of want to go our own separate ways," she said.

(Audrina is trying to be a movie star -- but what about when movie stars make fun of her? What does Audrina think of the Funny or Die clip, featuring James Franco and Mila Kunis, that spoofs "The Hills"? Find out on the Newsroom blog.)

While Patridge is concentrating on film, she admits that one of those post-"Hills" paths might lead her to her very own show. Asked if she would ever want a spin-off, similar to Whitney Port's upcoming "The City," Patridge told MTV News that it was one of the many options on the table.

"You know, I have a few things in the talks," she said. "I've been talking to different people about that. I've considered it ... so it's definitely an option I'd consider."

As to what that spin-off would focus on (beyond her, of course), or where it would take place, Patridge was mum. "That's something I need to sit down and really think about," she said.

What do you think? How long should "The Hills" continue and how should it end? Should Patridge get her own spin-off, or would you rather she concentrates on films? Sound off on all your thoughts below.