Strictly Come Dancing has revealed how the show picks its celebrities for each series.
And it all starts months before each season begins.
Strictly's 'talent executive' Stefania Aleksander has explained just how the cast is picked in an interview with the Strictly Confidential podcast.
Speaking about casting 2018's line up, she began: "You come up with ideas for the cast of Strictly, present them to the executives and commissioners, and together decide who we want to go for.
"The list is endless.
"We approach people that we really want to go after and we'd love to see on the show and then we meet them to have a chat about the show, and the commitment, and find out how much they want to learn to dance. Then we present that to the channel between us – it's a long process."
Stefania says the process begins as early as February, telling hosts Scott Mills and Amy Elizabeth last year: "It's not as simple as saying, 'Hey I want to do Strictly' and we go, 'OK, you're booked'. You have to represent for the family audience.
"It's a mixed bag – you don't want to replicate every year so you wouldn't go for another Holby City star [after Joe McFadden won in 2017].
"For me it's about surprises. I want them to go, 'Oh I didn't expect that'."
She added that the introduction of YouTubers - starting with Joe Sugg in 2018 - was all about "bringing in a new audience."
Stefania went on to admit not every celebrity who wants to take part makes the cut.
"We've all been there in life when we've been for an audition and you didn't get it," she said. "I'm very sensitive to that... I feel sad for them but genuinely we don't have the space for more than 15, which is a real shame."
Strictly Come Dancing continues Saturday and Sunday night on BBC One.
This weekend sees the show's traditional Halloween special.
The remaining celebrities will dance live once more for the judges and viewers before one more couple is sent home in Sunday's results.