Addison returned to 'Grey's Anatomy' and addressed Derek's death — and it will hit you in the feels

She’s back!

On Thursday night’s episode of “Grey’s Anatomy,” Kate Walsh made her highly anticipated return to the long-running medical drama, as her character, Dr. Addison Montgomery, returned to the halls of Grey Sloan Memorial Hospital — and to some old wounds that still needed tending.

Appropriately enough, it took a visit to the operating room for her to really start healing.

KATE WALSH (Eric McCandless / ABC)
KATE WALSH (Eric McCandless / ABC)

In “Hotter Than Hell,” the third episode of season 18, the neonatal surgeon found herself in need of support during a transplant procedure and requested the best help she could get — Dr. Meredith Grey, who's played by Ellen Pompeo. And after working so well together in the heat of the moment, the duo confronted something else they shared after the operation was over.

ELLEN POMPEO, KATE WALSH (Eric McCandless / ABC)
ELLEN POMPEO, KATE WALSH (Eric McCandless / ABC)

Addison and Meredith had their first private moment together in the elevator after the surgery, and it was a powerful one, too.

That’s where the ex-wife of Derek Shepherd, who was played by Patrick Dempsey, broke down about her own grief in front of his widow.

"I thought coming back here, to Seattle, to Grey Sloan, that he’d be here — that I would be able to feel that he was still here in the city that he loved, with the people he loved," Addison sobbed. "But he isn’t, and it's real. He’s not here. And I’m really sorry I’m doing this in front of you, because you’re the one who had to actually go through it."

But it was clear, six years after Derek's death, Meredith didn't feel defensive or possessive in response to Addison's outburst.

She felt compassion.

Related: Things were not so McDreamy on the set of "Grey's Anatomy" before Patrick Dempsey's stunning exit, according to a new book.

"Addison, he is here," she told the returning surgeon. "And he’s in his children, and they are very real."

Then Meredith offered up a way for Addison to really get the closure she clearly craved, adding, "I would love for you to come and meet them."

Before the tearjerker ended, Addison not only met Zola, Ellis and Derek, who goes by Bailey, she told them she was their dad's old pal "Addie," and quickly formed a sweet bond with Derek and Meredith's kids.

And fans weren't the only ones reaching for the tissues when it was all over.

"Well excuse me while I go shed a few tears…" Walsh tweeted after it aired. "Wow!"

"Truly blown away by everyone’s reaction and support for tonight’s episode," she continued in a post on Instagram. "Thank you all for making this night so special! 🥰 Feels like Addison never left ❤️"

And she's not going anywhere any time soon.

When Deadline first broke the news about Walsh's return in September, it was reported that she would star in several season 18 episodes.

And long before that news, in March, Walsh visited TODAY and revealed that she "would love" to get back to "Grey's," adding, "It just would be a matter of how to do it and when."