Jodie Whittaker has told how she collapsed in tears and had to be carried off after filming her last Doctor Who scenes alongside Bradley Walsh and Tosin Cole.
The actress, who became the first female to play the Doctor in 2017, said she felt "incredibly bereaved" by their departure.
While she is staying on for a third series as the 13th Time Lord, her two male sidekicks Graham and Ryan will leave for good in the festive special, which airs on New Year's Day.
Jodie, 38, said she could not be sadder to see them go.
"The fam as a four, is no more," she declared. "This will be the last time we see Bradley and Tosin.
"On a personal note, I feel absolutely devastated. Just purely knowing it was the last scenes between myself and those actors – both of them had to carry me to my trailer. I've not cried like that for such a long time.
"Brad couldn't cope with it at all. And Tosin was like 'I really can't cope with you getting so upset'. I was like "waah, waah waah."
That sums up how I feel. There was not a sense of relief, in any way. When you realise that it's the last moment these four characters will have, I felt incredibly bereaved - all of our journey has been together and we clicked like a family."
And joking about the fourth member, fellow companion Yaz played by Mandip Gill, she laughed: "And then I was like – don't leave me with her."
The Mirror revealed in March how Bradley and Tosin had quit the show, having each signed up for new drama projects.
Showrunner Chris Chibnall confessed he'd also cried over their exit in the festive special, called Revolution of the Daleks, which was filmed ahead of the pandemic.
"It's very emotional and we've all been in tears watching it. The special has lots of thrills, lots of spills, lots of humour, lots of Daleks and lots of emotion.
"We don't shy away from what it means for this family to have its final moments together. It was emotional off screen and on screen. I hope it feels like a good send-off for those two characters, whatever happens to them."
Walsh, 60, quit ahead of signing up for an ITV reboot of The Darling Buds of May, which was postponed because of Covid.
He said after filming ended on the last series of Doctor Who that he'd been left worn out.
"This is 10 months of ramming speed.
"It's tough. It's hard. It's relentless. It really is. This ain't an easy gig."
Cole, 28, has landed the lead role in US courtroom drama 61 Street.
In the Christmas special the Doctor is stuck in space prison and it's up to the trio on Earth to kick off the fight against the Daleks – with the help of John Barrowman as returning favourite Captain Jack.
Chibnall said that viewers never tired of the Doctor's best-known adversary.
"The Daleks are a design classic, a great British design, like the Mini, which keeps being updated. They have had a makeover for a very specific reason that you'll find out about in the story. They are a black variant with red lights, they've had a bit of a sheen polish."
He said they had also found some new skills.
"They move fast at certain points I can tell you – when they're flying through the air!"
Jodie said that despite their shortcomings, they were still frightening.
"It is interesting how scary they are. They're not very fast, but they are really creepy. As the Doctor, to have scenes where you are dealing with, or failing to deal with, such an iconic monster it feels as if we are putting our stamp on our time.
"To know that we've been butting heads with them is really great."
Chibnall said the next series, which started filming for BBC1 this month, has been totally overhauled because of Covid.
"We've reimagined it from the ground up so that people can work safely. The team at BBC Wales have been extraordinary at getting the show back on its feet again.
"We will be back with some very exciting, fun, thrilling, mad episodes after this special has aired."