Grey’s Anatomy will bid farewell to 2009 later this season when the Seattle Grace staff celebrates Thanksgiving, Christmas and New Year’s - all in one very special installment.

“We’re pretty excited,” show creator Shonda Rhimes tells TV Guide of the big Grey's Anatomy event. “We’ll be watching time pass as we take the audience into the new year.”

Sadly, this isn't to say all the news is warm, fuzzy and joyous.

From the sound of it, the Season Six drama shifts away from medical and professional drama and focuses instead on characters’ personal hopes, dreams and disappointments.

Over the holidays, “people feel like something magical or momentous should happen,” Rhimes explains, but certainly speaks the truth when she says “But often nothing does.”

Among other story lines, we'll be seeing how Bailey became Bailey.

In the episode, we will meet Miranda Bailey’s (Chandra Wilson) mother, whom Rhimes describes as “more Bailey than Bailey. You’ll finally see where Bailey gets her stuff.”

In between unwrapping gifts, Mark and Lexie’s happiness will be rocked by the arrival of a character from his past who Rhimes says will cause them “to fall on hard times.”

Meanwhile, over on Grey’s Anatomy's sister show, Private Practice, Addison Montgomery (Kate Walsh) will be getting a surprise visit from her dad, whom she calls “The Captain.”

He's played by Stephen Collins, while her mom, Bizzy, will be played by JoBeth Williams.

Over a three-episode arc, kicking off in mid-November, Rhimes says Addison will finally get to the bottom of some more of the redhead's “shocking family secrets.”

Well, it is the holidays, right?

Was Chandra Wilson's awesome stint on Private Practice just the first of several such crossovers to come this season on Shonda Rhimes' sister shows? Here's E!'s latest ...

Q: I loved last week's Grey's Anatomy-Private Practice crossover with Bailey! She killed it. Is there anything good you can share on Grey's Anatomy or Private Practice?

A: I'm told by insiders that there should be at least two more crossovers before the season is through, though they have yet to hammer out specific details.

Who do you think should do the crossing honors?

As for one particular rumor going around - that there will be an upcoming plot involving for Justin Walker (Dave Annable) of Brothers & Sisters to cross over to Private Practice (Justin is now in medical school), a rep at ABC says that's actually not happening.

Aww. Too bad. But there are other good options.

Below are some photos from this Thursday's episode, "I Saw What I Saw."

After a burn victim unexpectedly dies in a chaotic ER, the Chief and his board members are forced to interrogate each individual resident to find the culprit. In turn, the residents, new and old, are forced to defend their actions in an effort to save their jobs.

Naturally, this should lead to even more tension among the Seattle Gracers and Mercy Westers as the melting pot that is Grey's Anatomy continues to be shaped before our eyes.

Click to enlarge the pics from "I Saw What I Saw" and comment below:

What did YOU see?

No, we're not talking about the tagline for ABC's FlashForward. That's what the doctors of Seattle Grace will be asked at great length next week, with more versions of events regarding what happened to a patient than the Chief will be pleased to hear.

Here's the first promo for "I Saw What I Saw." Looks like plenty of tension in the air, like last night if not worse. Let us know what you think will happen on this episode ...

Welcome to the 180th week of the Grey's Anatomy Insider Caption Contest.

This week's Caption Contest winner is bex. Congratulations on a job well done! As always, we've posted the winning entry beneath the Grey's Anatomy photo below.

Honorable mentions go out to David, marriedmymcdreamy and April_J.

Thanks for playing and good luck again next week ...

Izzie: You mess with me, you get the whole trailer park. Willy Wonka won't save you either. Back to loompa land evil spawn!

[Reed continues to smile as we are all aware that oompa loompas are small, dim-witted creatures only concerned with candy and their abnormal orange-ness]

Izzie Stevens was fired last night on "Invasion."

But she will be back on Grey's Anatomy at some point next month.

We know this because the (appropriately named) veteran actor Joel Grey, 77, will appear in a November episode as a blast from Izzie’s past - her old high school teacher.

“It’s a pretty amazing episode,” says show creator Shonda Rhimes.

“It turns out he was the teacher who convinced Izzie (Katherine Heigl) she was more than just another girl from the trailer park. And now he’s in need of her help.”

What role will Izzie's former mentor have on her future?

This will be Heigl's only episode in November sweeps, as she is off shooting a movie. Her character's firing last night cleared the way for her to miss five episodes.

Rhimes is also considering bringing back Sharon Lawrence as Izzie’s mama, Robbie Stevens, who was last seen at the end of Season 5 at her ailing daughter’s bedside.

“We love Sharon,” Rhimes says.

Last night's Grey's Anatomy saw the world of Seattle Grace as we know it turned on its head. The Mercy Westers descended, wreaked havoc and one of our own got fired.

How long will Izzie Stevens be gone? Did she really leave Alex? These questions remain up in the air for now in the wake of her abrupt departure at the end of the episode.

Lexie, Alex and Cristina each did whatever they could to upstage their new Mercy West counterparts, with largely failed results. Our people are looking dazed and confused.

Elsewhere, Callie's dad returned to convert her, but he was the one who saw the light. Bailey's patient was almost killed by Izzie, driving her to L.A. and Private Practice.

For the full rundown of events last night, here's our recap of "Invasion."

Richard lets Izzie go. She does not take the news well.

Within the episode main page you can find links to Grey's Anatomy quotes, music, photos and videos, which we're working on compiling. These are available for all episodes!

What did you think of last night's Grey's Anatomy? Share!

Last night, Miranda Bailey crossed over from Grey's Anatomy and pulled double duty by stealing the show on Private Practice immediately after, continuing her same story line.

The final hope for the kidney transplant patient whose treatment Izzie botched was in L.A., and it was quite controversial - her HIV-infected sister was the last possible donor.

Bailey butted heads - and showed some palpable chemistry - with Taye Diggs' Dr. Sam Bennett, while Addison's emotional affair with Noah last season came back to bite her.

Oh, and Pete and Sheldon finally know, thanks to a paternity test the latter insisted on given the strange parenting arrangement for Lucas, who the father of Violet's baby is.

Our sister site, TV Fanatic, has you covered with a full recap of "Right Here, Right Now," as well as quotes, spoilers, casting news and more from the world of Private Practice.

Mark Wilding, the head writer on "Invasion," has a lot of explaining to do.

Where the heck did Izzie go? Will she be coming back? And what is with these people coming in and tearing down the foundation of the Seattle Grace we know and love?

Below are some excerpts from Mark's column, with a link at the bottom to her full entry. It's always interesting to get a fresh take from the people who put it together:

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Izzie is gone. Fired by the Chief who, these days, is looking an excuse to fire ANYONE. Maybe she went back home. Or to visit some friends. Or just took off for points unknown.

But yes, Izzie Stevens, third year resident and surgical rising star, no longer works at Seattle Grace/Mercy West. The hospital, new name and all, is in her rear view mirror.

George’s death, her stage four cancer, coming back to work too soon – it all proved too much – and now she’s off to God knows where. More on Izzie and broken-hearted Alex later.

Reed, Charles, April and Jackson. The Mercy West crowd. Just as insecure and uncertain about their new situation as our people. And our residents are understandably nervous because, like invaders of any kind, these MW guys are a threat. They’re smart, they fight dirty.

The new actors – their real names are Nora, Robert, Jesse and Sarah - were a blast to work with. I probably should have known all their credits and what shows they’ve been on before we started shooting but I didn’t. And none of that mattered because they were all so strong.

Lexie and April. We got to see a new side of Lexie Grey. One who can fight dirty and be a mean if she had to be. That is until the passive-aggressive April herself is undone when she finds out Lexie has read her notebook with all her little self-help homilies. 

Izzie was looking over her shoulder from the get-go.

Charles and Izzie. Izzie thinks she’s found someone who maybe just maybe, reminds her a little of George. And it goes to Izzie’s trusting instincts and her need to fill the void left by George that she quickly gloms onto a sympathetic soul like Charles.

But, as the Chief tells her later, it’s a different era. The old rules don’t apply – be it with friendships or with jobs. A lesson that Izzie learns not just once in this episode, but twice.

Jackson and Cristina. I especially loved Cristina Yang finally deciding to hold up the white flag of surrender. Throwing in the surgical towel. And as for Sandra Oh - in the scene when she’s crying with Meredith (and pining for Burke), well, my God, she was superb.

Alex and Reed. Reed is not a big person. Still, as Alex finds out, she can flat out play this game. As much as I loved their competitive dynamic, each trying to outmaneuver the other one, I also liked showing our doctors as less than compassionate with a patient.

Back to Izzie. When you tell the Chief of Surgery that you NEED this job, that you’ve got nothing else in your life, DESPITE the fact you’re married, you are in a very bad state indeed.

I understand the part about sneaking off without telling anyone after you’ve been fired but to just leave your husband a note – that’s absolutely brutal. No wonder Alex has issues.

Finally, I want to talk about Callie and Arizona. It was Hector Elizondo’s idea to use the cards. He didn’t think his character would know that stuff of the top of his head, which is how I originally wrote it. And he was right. And it worked beautifully.

And that final scene when he and Callie are outside the hospital and he’s asking her if she’ll still get married, still have kids. I really, really liked that scene. 

Follow the link for the entirety of Mark's blog ...

You can't pray away the gay. But you must at least try - however in vain - to hold the ship until your last ... dying ... breath. Words to live by, Grey's Anatomy style.

The invaders from Mercy West invaded, as advertised, although the consequences were more severe than anticipated for the doctors we love, as well as their patients.

Will Izzie return? Where did she go? That we can only wait and see.

Tells us, what did you think of tonight's Grey's Anatomy?

Our recap of "Invasion" will be posted soon. In the meantime, tell us how you felt about the show tonight by commenting below and by voting in the Insider's survey.

As always, the Grey's Anatomy Insider staff will post quotes, music, news, photos, spoilers and all things Grey's Anatomy as soon as possible! Thanks for visiting us!

"Invasion" was ...