Doctor Who: Flux reveals guest character details in new images

But there's also a whole array of new characters joining the Doctor too, with series 13's special serialised format meaning they could appear over multiple episodes.

"I did love the stand-alone episodes but this way feels like I have longer to explore relationships with other characters," series star Mandip Gill said in a release. "Yaz is able to develop a much deeper relationship with them that doesn’t end at the end of an episode.

"On a personal level I have really enjoyed having such amazing guest leads around for a longer period of time and sharing this experience with them."

And now, the BBC has released some first-look images of these new friends (and foes) in costume, along with some intriguing new details about what we can expect from them. But who are they and what do they want with Thirteenth Doctor?

Read on to find out everything we know about Doctor Who series 13's new characters.

Annabel Scholey plays Claire

The Split and Britannia star Annabel Scholey joins the cast as Claire. “I am absolutely thrilled to be a part of the 13th series of Doctor Who," she said. "It was a lot of fun to film and I enjoyed every minute I spent with the amazing cast and crew."

We don't know much about Claire yet, but it looks like she'll make her debut in the Halloween episode, and rumour has it that she was spotted filming with Weeping Angels during production.

Craig Parkinson

We don't know his name yet, but Line of Duty's Craig Parkinson will play "one of [the] greatest characters of the series", Doctor Who boss Matt Strevens revealed. It also looks like he'll be sporting one of the greatest hairstyles in the series, judging by this first-look image.

Gerald Kyd

Kyd (Cold Feet, Britannia) is no stranger to Doctor Who, having voiced Martin Regan, Sir Robert Devere and Stephen Mulryne in the Big Finish Doctor Who audio story 1963: The Assassination Games and Lt Maurizio Savinio in Aquitaine.

It looks like his character for the main Doctor Who story is brand new, however, sporting the uniform of a Crimean War soldier (and possibly pitted against the Sontarans).

"I absolutely adored being a part of such an iconic show," Kyd said. "There’s nothing like it. The history, the stories, the utter devotion of the fanbase.

"I am honoured to now count Doctor Who as a credit. Oh, and the highlight amongst highlights was working with the wonderful, hilarious and irrepressible Jodie Whittaker."

Kevin McNally plays Jericho

Mandip Gill revealed the name of Kevin McNally's character is Jericho, who is in "several episodes and so Yaz is able to develop a much deeper relationship with [him] that doesn’t end at the end of an episode".

Strevens added that Mandip Gill and John Bishop "got to spend the most time with him" and teased "the whole dynamic between those three actors was taken to another level and that was a joy." Intriguingly, this suggests that the TARDIS team will be separated across the series - so will Whittaker's companions be abandoned?

Nadia Albina

Nadia Albina's character's motives remain very much a mystery at this stage, but the first look image does seem to place her in present day Earth, so that's something. Rumour has it that her character may also have some romantic history with John Bishop's Dan, though that's not been confirmed at this stage.

Blake Harrison

We don't know who Inbetweeners star Blake Harrison will be playing just yet, but judging by the first-look image of his character, it seems as though he's like he's facing some hard times - and he looks to be sharing plenty of scenes with Thaddea Graham's character.

"It’s a pleasure to be a part of this huge show that has such a passionate fan base!" Harrison previously said. "I hope all the Doctor Who fans enjoy the new series and my role in it."

Paul Broughton and Sue Jenkins

Ever since the BBC released the first-look images, there has been much speculation that these two could be Dan's (John Bishop) parents Eileen and Neville.

Separately, fans have also wondered whether this picture could be from the 80s, thus suggesting Dan might not be from the modern day. It's just a theory at this point - it's probably just an old car - but in Doctor Who, you can't rule anything out.

Rochenda Sandall

Our first look at Rochenda Sandall's unnamed character reveals she looks like a human, instead of a monster as we had previously speculated. Better start looking for another candidate for the mysterious Ravagers...

Sandall has implied on Twitter that she'll appear in the first episode of the series, though given that characters are expected to appear in more than one episode this year it's not a big clue to what we might expect.

Penelope Ann McGhie

McGhie is rumoured to be playing a character called Mrs Hayward, and looks to be from Earth's past (unless she's just a fan of vintage fashion).

"Doctor Who was a total joy to work on," McGhie said. "Everyone was so welcoming and generous that I really felt part of the team.

"Having watched the show from behind the sofa over fifty years ago, and then again with our daughter when the series was revived, I can’t believe how lucky I am to be part of the adventure!"

Sara Powell

Powell has been rumoured to be playing legendary Crimean war nurse Mary Seacole, one of this series' "celebrity historical" figures, and this picture (along with other hints at a Crimean War storyline) certainly do seem to be nodding towards that possibility.

"A role in Doctor Who is top of any actor's wish list," Powell said. "To say I leapt at the chance is something of an understatement.

"Working with Jodie Whittaker - an iconic Doctor and actor - was also on my list. She was a legend. As were the cast and crew: indoors, outdoors, in winter, in Wales in the rain and mud, everyone wearing masks and being tested every five minutes: I loved stepping onto their ship and riding with them for a while."

Steve Oram

Oram might be playing real-life Liverpudlian eccentric Joseph Williamson, known for excavating a network of tunnels under his home city (which is also the setting for Doctor Who: Flux's first episode) alongside his business interests and philanthropy.

It seems likely these tunnels could play a part in the Flux storyline, so watch out for Oram in earlier episodes of the series.

Thaddea Graham

Graham's character remains a mystery, though the number of scenes she shares with Harrison's robed character and shots of her in red foliage from the trailers has had some fans wondering if she'll appear in flashbacks to the Doctor's home planet of Gallifrey. Certainly, she looks to be from a more futuristic age than many of this year's other guest stars.

"The whole cast/ crew welcomed me with open arms into the iconic Doctor Who family of which it is an absolute privilege to be part of," Graham said. "It's a real honour to share the magic of this universe with them and, of course, our wonderful audience this October!"

Doctor Who: Flux kicks off on Sunday 31st October. Check out more of our Sci-Fi coverage or visit our TV Guide to see what’s on tonight.