It's a 10 in honor of Len.

The competition show saw some of its most beloved pros return to the ballroom for a touching tribute to late head judge Len Goodman, who died in April 2023 at age 78.

Maks Chmerkovskiy, Kym Johnson-Herjavec, Tony Dovolani, Anna Trebunskaya, Karina Smirnoff, Louis van Amstel, Mark Ballas and Edyta Śliwińska joined the current pros on the Oct. 24 episode to dance in Len's honor.

The heartbreaking number—choreographed by Jenna Johnson and Val Chmerkovskiy—was set to a song Len loved, Henry Mancini's "Moon River," with a dance style that he would have certainly approved—the waltz.

Before the dance, Tony shared in a pre-recorded package, "Tonight, we'd like to tip our hats to Len one last time." 

The performance finished with a spotlight on Len's chair, as his voice is heard saying, "All good things have to come to an end."

The ballroom was swept up with emotion as both the pros and judges broke down in tears. Bruno Tonioli and Carrie Ann Inaba consoled one another as the audience applauded. 

Before their performance, the dancers gave a glimpse into how Len—who died of cancer four months after announcing his retirement from DWTS—became a household name in America, as well as in their own hearts.

"To come back and read that love letter or dance that love letter to him, saying thank you for his input into our world, I think it's a no-brainer," Kym said of her decision to return to the ballroom. "We are all excited and grateful to have that opportunity and for the show to be able to give that to us."

"One of the things I'm most thankful for is being able to judge alongside Len," Derek Hough said through tears. "I was able to spend a little more extra time with him and for that, I'm really thankful."

A teary-eyed Anna expressed, "I miss giving him hugs and seeing how he is and I miss him a lot," while Louis reflected, "It's an honor that I can say that Len judged me."

Looking back at the beloved Brit's judging style, Maks noted, "Getting criticized by Len was never easy, but getting that 10 made it all worth it."

The pros also gave viewers a look into Len's personal life, which included sweet videos of the dance teacher laughing and goofing off with Derek behind the scenes. And of course, they remembered his admiration for his loved ones.

"What he kept sacred and private was his love for his wife and his family," Julianne Hough explained, as pictures of Len and his wife Sue Goodman and son James Goodman flashed across the screen. 

The emotional video highlighted some of Len's best moments from when he waltzed into America's hearts.

"Well, I love you too," he said to an off-camera Derek, "it's been so much fun."

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