Major spoilers for series 3 of Doctor Who ahead.
Doctor Who dropped its third episode of the new season, Boom, and a pretty significant character just made a cameo.
The latest episode of the sci-fi series – starring Ncuti Gatwa as the Fifteenth Doctor – saw the Doctor and companion Ruby Sunday (Millie Gibson) arrive on Kastarion 3 and face off against a deadly threat.A live landmine nestled right under the Doctor’s foot.
During the episode, written by former showrunner Steven Moffat, the audience discovers that Kastarion 3 is in the midst of a devastating war with a religious military group known as the Anglicans on one side of it.
After one of the soldiers, John (Joe Anderson), is sadly killed we discover his daughter, Splice (Caoilinn Springall), is living on a nearby settlement and being watched over by Mundy Flynn portrayed by Varada Sethu.
That’s right, Splice’s caretaker is none other than the season two companion, as announced by the BBC in April.
At the time, the Andor actor said it was ‘an honour to be part of the Whoniverse’ and that she would join the TARDIS team in 2025. So what on earth is she doing in the show a whole year early?
During the episode, Mundy clearly has unspoken feelings for fellow soldier Canterbury aka Canto (Bhav Joshi).
When Splice goes to track her father down on the battlefield Mundy and Canto follow, causing them all to converge around a terrified and confused Doctor and Ruby.
Needless to say, the future companion doesn’t get off to a good start after almost attempting to murder the Doctor before being convinced otherwise.
By the end of the episode, Mundy is faced with tragedy after Canto is accidentally killed by a rogue battlefield AI ambulance (played by Susan Twist).
But instead of hopping on the Tardis to join the Doctor and Ruby, Mundy remains on the planet, ready to care for Splice.
This is not the first time a companion, or even a Doctor, has been introduced long before their run on the show.
Catherine Tate first starred as Donna Noble in the 2006 Doctor Who Christmas special, The Runaway Bride.
Although she was originally only meant to guest star, her popularity was so great that she returned for the fourth season from 2008 to 2010.
Meanwhile, series 5 companion Karen Gillan showed up in the season 4 episode The Fires of Pompeii as a Soothsayer. In the very same episode, future 12th Doctor Peter Capaldi also featured as Pompeii resident Caecillius.
But, there is no doubt that showrunner Russell T Davies and writer Moffat would have been aware that Sethu would be making a return as a full-time companion, making this guest role much more purposeful.
Moffat has pulled something similar before. In season 7 opener Asylum of the Daleks, we are introduced to Oswin who returned as companion Clara Oswald (played by Jenna Coleman) several episodes on.
Her premature appearance ended up tying into the plot as it was later revealed her character was trapped in the Doctor’s timestream.
In an interview with The Hollywood Reporter, Moffat teased: ‘She’s there! We’re just going to do Clara again. So it’s fun, isn’t it? It wakes you up. You think, “Ah, there she is!”‘
As for how and when Mundy will return remains to be seen, but for now she seems to be slyly slipping through the net. As Moffat said, ‘There is a plan. That’s all I’m telling.’
Doctor Who returns with 73 Yards on Saturday, May 25 on BBC One and BBC iPlayer.
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