'Doctor Who' showrunner Chris Chibnall has been planning the return of Captain Jack Harkness since 2019.
The BBC One sci-fi show's festive special 'Revolution of the Daleks' will see John Barrowman return as the intergalactic time traveler to help the Doctor (Jodie Whittaker) and her companions battle her greatest enemy.
Chris admits he first came up with an idea for Jack's return in the early days of 2019 and the pair finalised the comeback over numerous "phone calls" and "not-so secret meetings" backstage at the performer's concerts.
Speaking in a Q&A, Chris - who included Jack in the Series 12 episode 'Fugitive of the Judoon' as a teaser for fans - spilled: "It’s been cooked up for a long time, we knew he would be coming back for this special so we back laid him in the Judoon episode in the previous series.
"It was cooked up over lots of phone calls and not so secret meetings at John Barrowman concerts. He smuggled me backstage and we had a conversation back in the days of early 2019. I knew I really wanted Captain Jack to meet the Thirteenth Doctor and it had been a long time since he’d been on screen in 'Doctor Who', it was well overdue."
Chris specifically wanted John back as the character - who made his first appearance in the show back in the 2005 two-part story 'The Empty Child' and 'The Doctor Dances' opposite Christopher Eccleston's Ninth Doctor - in a festive special because he likes to think of those stories as being a "treat" for fans.
And given the character's history with the Daleks there was no better foe for him to come back and face with the TARDIS team.
Chris added: "With festive specials you want it to feel like a treat, and there’s no bigger treat than John Barrowman’s Captain Jack.
"He’s funny, he’s dynamic, he’s a big part of 'Doctor Who' history, I knew we’d need a character who could help the family in the Doctor’s absence. He has a particular perspective on the Doctor and being without her or him. Jack brings a lot of things to the table, really, and he has a really great coat.
“He has past history with Daleks, seeing as they killed him, a small detail in his life, he’s going to be up against them and he’s going to be really important to Graham and Ryan. And the moment when he finally meets the Doctor – should it happen – is going to be great."
John, 53, will also be joined in the episode by Bradley Walsh, Tosin Cole and Mandip Gill, who play companions Graham O'Brien, Ryan Sinclair and Yasmin Khan respectively, Chris Noth reprising his role as Jack Robertson - previously seen in the episode 'Arachnids In The UK' - and Dame Harriet Walter.
'Revolution of the Daleks' will air on New Year's Day (01.01.21) on BBC One and will be Bradley and Tosin's final appearances in the series.