After 13 years the annual Doctor Who Christmas special is pretty much a British television tradition. But every so often there’ll come one that stands out from the usual festive fluff, with this time of the year reserved for the current Doctor to bow out and pass the torch onto the next incarnation. Following in the footsteps of 2009’s The End of Time and 2013’s The Time of the Doctor , Twice Upon a Time serves as the swansong for Peter Capaldi’s twelfth Doctor and the debut of Jodie Whittaker in the role, with Steven Moffa t also stepping down as showrunner before Chris Chibnall takes the reins. The episode also sees the return of the very first Doctor – now played by David Bradley on the back of his portrayal of William Hartnell in the excellent 50th anniversary biopic An Adventure in Space and Time .

After 12 (mostly) fantastic weeks, but the time has finally come for Doctor Who series 10 to come to an end. Along with that comes goodbye to Peter Capaldi as the Doctor , Michelle Gomez as Missy , Steven Moffat as showrunner and quite likely Pearl Mackie  and Matt Lucas as Bill Potts  and  Nardole  too. Well, this is true for some of those anyway as we already know Capaldi and Moffat will both be returning for the Christmas special before handing the reins over to new showrunner Chris Chibnall and the currently unknown new Doctor. But regardless regeneration is in the air, and following the sheer horror of World and Time Enough there's two Masters, a newly born army of Cybermen and Bill's transformation into a Cybermen to deal with as The Doctor Falls ...

It's been a fun ten weeks, but now the end is finally approaching. It's time to begin bidding farewell to Peter Capaldi  as the 12th Doctor , Michelle Gomez as Missy , Steven Moffat as showrunner and potentially Pearl Mackie as Bill Potts too. As Doctor Who series 10 draws to a close we begin the two-part finale with World Enough and Time - written by Moffat and directed by Rachel Talalay , who previously directed the two-part finales for both series eight and nine. As well as bringing back the original Mondasian Cybermen to screens, World Enough and Time also features the much-publicised return of John Simm as the Master , making this the first multi-Master story put to screen.

Doctor Who has never been one to shy away from a real-life mystery. After all, anyone who's seen The Chase will know that the crew of the Mary Celeste disappeared after the Daleks landed on it while chasing the Doctor through time and space. So this week it's tackling the real fate of the Ninth Roman Legion , which mysteriously disappeared and is thought to have been defeated by Celtic tribes in the north of Britain. The Eaters of Light is also a particularly notable episode because of it's writer Rona Munro - the first person to write for both the modern and classic iterations of the show, having previously written the show's "final" episode Survival in 1986.

The most highly anticipated Doctor Who episodes are usually the ones that feature the return of classic monsters, so it shouldn’t be any surprise to hear that Empress of Mars was particularly high up on series 10’s most hotly tipped offerings. After making their long-awaited modern debut in 2013’s Cold War , Mark Gatiss brings the Ice Warriors back on their home soil as well as making a brand new addition to the Martian hierarchy.

With Bill  having bargained with the Monks for the Doctor 's sight at the end of The Pyramid at the End of the World , Earth is now theirs for the taking as the Monks Trilogy reaches its thrilling conclusion in The Lie of the Land. This part of the story takes on a new writer yet again, having been penned by Toby Whithouse  in his first (and only) series ten episode. He's certainly no stranger to Doctor Who  though, with the likes of School Reunion, The Vampires of Venice, The God Complex, A Town Called Mercy and Under the Lake / Before the Flood among his writing credits.

After receiving a warning from his virtual self in last week's Extremis , the Doctor must now prepare for the incoming monks invasion in the real world - all while still keeping his blindness a secret from companion Bill. The Pyramid at the End of the World is the second part of series 10's "Monk's Trilogy", co-written by Steven Moffat and Peter Harness . This is the fourth story Harness has penned for Doctor Who , following on from series eight's Kill the Moon and series nine's Zygon two-partner The Zygon Invasion and The Zygon Inversion (the latter of which was also co-written with Moffat).

Note: Extremis is an episode almost impossible to review without discussing spoilers, so this review will be particularly spoiler-laden. You have been warned! Last week’s episode Oxygen raised the stakes pretty significantly when not only was the Doctor left blinded during his adventure aboard a deep-space mining system, but the TARDIS medical systems were also subsequently unable to cure him. Now not only is the Doctor left vulnerable, but he’s also determined to keep his condition a secret from Bill . Blindness won’t slow down though, and it’s business as usual in Steven Moffatt’s Extremis – the first episode in a loosely connected “Monks Trilogy”.

If there’s been one thing wrong with series ten of Doctor Who so far it’s that there’s been a distinct lack of Nardole . Matt Lucas’ character from The Husbands of River Song becoming a series regular came as a surprise, but since then the mystery surrounding him has only heightened as we discovered he was tasked with keeping the Doctor grounded on Earth. Thankfully this time he’s joining the Doctor and Bill on their latest adventure, in the series’ fifth episode – Oxygen . This episode was written by new fan-favourite Jamie Mathieson , who previously penned Mummy on the Orient Express and the excellent Flatline as well as co-writing The Girl Who Died with Steven Moffat.

After a trip to the future and a quick jaunt to the past, it's now time for Doctor Who to do the other thing that it's managed so well at in the past - good old fashioned present day horror. The fourth episode in series 10 of the modern era is Knock Knock - written by series newcomer Mike Bartlett and guest starring the legendary David Suchet , perhaps most famously known for his role as Hercule Poirot in Agatha Christie's Poirot. Following the episode's original airing a special "surround sound" edition was also released by the BBC , giving the viewer even more immersion into it's creaky wooden house setting.

Watch Doctor Who for long enough and you'll inevitably start to see patterns forming, but even then this current season definitely feels like a throwback to when the show first returned back in 2005. Not only is Bill Potts probably the closest proxy there's been to Rose Tyler since her departure, but now her experiences with the Doctor are pretty similar so far as well. After their initial meeting on present day Earth, both were flung off to the far future before returning to Victorian England for their third adventure. Thin Ice (not to be confused with the Big Finish audio story of the same name) was written by Sarah Dollard , who made her Doctor Who debut last series with Face the Raven .

After dodging alien puddles and being introduced to the weird and wonderful world of the Doctor in last week's Doctor Who episode The Pilot , new companion Bill Potts is now ready to take her first proper journey in the TARDIS . The second episode of this year's series is entitled Smile , and written by children's writer Frank Cottrell-Boyce. This episode is Cottrell-Boyce's second Who outing, having previously penned In the Forest of the Night back in 2014. With that particular episode meeting very mixed reviews from both fans and critics, many were especially interested how this one would turn out.

After a year's absence Doctor Who has finally returned to television screens for another full series (its tenth since the show's relaunch in 2005, and 36th in total), and it's already promising to be a year of both hellos and goodbyes. While this newest set of episodes introduces brand new companion Bill Potts (played by Pearl Mackie ) to the Whoniverse, by the end of its Christmas special Peter Capaldi 's time as the Doctor will be over and along with it Steven Moffat 's time as show runner. But it's a good few months until Chris Chibnall 's reign begins and we still don't know who's going to be cast as the 13th Doctor, so in the meantime let's just focus on the series at hand. This year kicks off with the cleverly titled The Pilot , which not only references the story itself but also seemingly acknowledges the "fresh start" approach a new companion often brings to the show.