The Hills Season 3 Finale Featuring Lauren Conrad

The half-hour, third-season finale of The Hills on December 10 will be only a small part of a big two-day bash MTV is planning for its top reality TV series.

On the big night, MTV and the cast will present The Hills Finale: Live in Hollywood, broadcast live from L.A. hot spot Area, beginning at 8 p.m.

The finale itself airs at 10 p.m. ET, followed by a live after-show, during which the ladies will answer questions from viewers and then, like, OMG, totally make “an announcement that will leave fans wanting more,” according to MTV.

The audience at the live show will include up to 40 winners of “The Hills Biggest Fan Contest” - which is accepting video submissions through December 3 from fans explaining why they love the Laguna Beach spin-off series.

"I gotta be honest, I haven't seen the final episode yet," The Hills star Lauren Conrad told People on Thursday. "I know that something happens in our lives, but I don't know what they're showing... Something very exciting happens in my life. I can't tell you what, obviously, because it has to air, but it was a life-changing something." The Hills' finale will actually kick-off on Sunday, December 9 at 12PM ET/PT when MTV airs The Hills: Lauren Looks Back, a two-hour "video scrapbook" that will follow Conrad from her senior year at Laguna Beach High to the life she currently leads.

While Lauren Conrad is keeping mum on the "life-changing" decision she makes during the finale broadcast, People reported she's been offered another opportunity to move to Paris, a chance that was first presented to her during The Hills first-season finale.