Doctor Who fans will prepare to say goodbye to Peter Capaldi as the Time Lord when the 10th series concludes tonight.

Capaldi is thought to be bowing out in the final episode of the current series, although it is not yet known if his regeneration will be taking place just yet.

Last week’s episode included a major hint that the regeneration – which sees one Doctor transform into another physical form – could happen in the season finale, rather than in this year’s Christmas episode as initially believed.

In Saturday night’s final episode, titled The Doctor Falls, the Doctor is seen facing up to the Master, played by John Simm, and Missy, played by Michelle Gomez, while the Mondasian Cybermen are now on the rise.

In a double blow to Doctor Who devotees, the series conclusion also marks the final effort helmed by Steven Moffat, who has been in charge of the show as head writer and executive producer since 2010.

Moffat has previously described the episode as a “bloodbath”, and added that the Christmas episode – in which Capaldi will appear – will be about “redemption”.

He told Doctor Who Magazine earlier this year: “I kind of do the angst in the series finale.

Doctor WhoThe Doctor, The Master and Missy (Simon Ridgway/BBC)

“You’ll see how this pans out when you see the show, but finales are better at ‘last falls’, and moment of reflection, and anguish, and bloodbaths – which it certainly bloody is!

“Whereas, Christmas Day isn’t a great day to kill off a children’s favourite. It can be sad – and it is – but to actually kill off lovely old Doctor Who is not what you want to see on Christmas Day.

“So it will be a tale of redemption, and hope, and deciding to carry on, instead of being a tale of the Doctor falling.”

Capaldi became the 12th Doctor in 2013, following in the footsteps of his predecessor Matt Smith, and announced his departure from the show in January this year.

Peter CapaldiPeter Capaldi as The Doctor (Ray Burmiston/BBC)

It is not yet known who will replace him in the role, although actors including Kris Marshall and Phoebe Waller-Bridge have been the fan and bookies’ favourites to step into the Tardis.

Moffat will be replaced by Broadchurch creator Chris Chibnall, who will take over the role as executive producer of Doctor Who next year.