While Jodie Whittaker’s swansong episode as the Thirteenth Doctor featured a lot of previous Doctor Who companions, two Tenth Doctor characters were also planned to make brief cameos at the end of the story.

One companion would’ve made a lot of sense; the other… decidedly less so.

The special, which celebrated the 100th anniversary of the BBC, included a scene where former companions of the Doctor met up in a “Companion Support Group”, like an AA meeting for people who have travelled in all of time and space in the TARDIS. That group included Ace (Sophie Aldred) and Tegan Jovanka (Janet Fielding), who made extensive appearances in The Power of the Doctor, plus Jo Jones (Katy Manning), Mel Bush (Bonnie Langford), Dan Lewis (John Bishop), Ian Chesterton (William Russell), and more.

And according to the original script, Martha Jones, played by Freema Agyeman, was due to appear too!

Martha, as far as we know, still lives on present-day Earth, sometimes a member of UNIT (indeed, Kate Stewart, played by Jemma Redgrave, was in the group), sometimes seconded to Torchwood, so it makes perfect sense for her to be there too. The other character due to appear, however, is a little more puzzling.

So who was it? Jackie Tyler (Camille Coduri), mother of Rose.

And she’s trapped on a parallel Earth.

How might she have appeared? Perhaps via a laptop… with interdimensional capabilities?

Oh, who knows? Writer, Chris Chibnall, was likely just betting on who might be available during scheduled filming dates. As it turned out, Agyeman and Coduri apparently weren’t free; neither was Tosin Cole (Thirteenth Doctor companion, Ryan Sinclair), who was pencilled in to cameo alongside his peers, Graham O’Brien (Bradley Walsh) and Yasmin Khan (Mandip Gill) but ultimately didn’t.

Some of you might complain that we classed Jackie as a companion, but she did travel in the TARDIS and even kissed the Doctor, so she’s at least on a level with Grace Holloway…