One of Hollywood's biggest mysteries has finally been solved -- the whereabouts on Oscar night of Best Actress nominee Renée Zellweger (search), who disappeared after losing to Nicole Kidman. (search)

Her vanishing act, she insists, was not sour grapes but instead the needs of the love of her life: her ailing 14-year-old dog, Dylan.

"I wasn't crazy about the parties," she admits, "because at that point I had gone to about 960 pre-parties. So at the end of the Oscar show I thought, 'If I could do anything in the world right now, to celebrate this night and what it means and what this experience has been about, what would it be?'

"And I thought, 'I'd love to kiss my dog on the nose.' So, I thought, 'I'm going to go home and do that.'"

As she was leaving the show, a man opened the door for her -- and accidentally stepped on her blood-red, form-fitting, lace designer dress, ripping it badly.

"The tear exposed something that probably shouldn't make an appearance at the Vanity Fair party," said Zellweger.

That made up her mind to head home, she says.

But when she arrived at her house in the Hollywood Hills, she discovered she had forgotten her front door key.

"You don't think about keys when you're putting on the dress on Oscar night and leaving the house," she said.

Fortunately she had a friend ready to help -- "He's Dave Palmer, a.k.a. Spider-Man" she laughs.

So as she stood and waited in her driveway, he managed to scale a wall and climb into the house through an open window.

When she walked into her living room, she discovered that poor Dylan had been having a "really bad night" in the absence of his mistress.

"I guess it was hilarious in a way," she says. "I took my dress off and put it in a safe place. Then I took Dylan out into the yard and gave him a little bath."

So instead of spending Oscar night sipping champagne, eating caviar and rubbing shoulders with some of the biggest stars in the business, Zellweger rolled up her sleeves and began to scrub her floors.

The decision to stay home was by now irrevocable. In fact, she says, it was a bit of a relief.

"It was actually one of those life moments that you don't ever forget because it was just a lot of realization that came with it, when you get deposited back into your own life where your heart resides," she said.

"After all of that, I just didn't feel like putting the dress on and going and being 'glamorama.' And it turned out to be a beautiful night because it gave me yet another reason to sit on the couch with my dog."

After relationships with Jim Carrey and George Clooney (search), Zellweger says she's single now - but hasn't given up on love.

"It's not that I'm too busy for relationships, but I don't meet anyone. Also, I think a relationship doesn't have to be sexual to be romantic. A couple of years ago on my birthday, I sat in a tree with a friend. That was very romantic. It doesn't have to be roses and all that stuff."

And, of course, there's always Dylan to come home to.