When the Tardis brought the Doctor and Clara to an underwater base in peril we were introduced to a host of new characters.
But who’s who among the besieged crew? And why do some of them look so familiar?
Moran – Colin McFarlane
Seasoned Doctor Who fans might recognise this Lincolnshire actor – and his voice – because he’s got quite a bit of Who history. Not only did he voice Bannakaffalatta, the cyborg Zocci who kisses Kylie in the Christmas special Voyage of the Damned, he also played General Pierce in Torchwood: Children of Earth.
Outside the Whoniverse he’s appeared as Police Commissioner Gillian B Loeb in Batman Begins and The Dark Knight, and also popped up during the ongoing ‘Who killed Lucy Beale?’ saga on EastEnders.
Cass – Sophie Leigh Stone
Sophie Leigh Stone’s journey to Doctor Who was a rather public one because the actress gained widespread acclaim for becoming the first deaf person to study at the Royal Academy of Dramatic Arts. And her stint at RADA served her well because she’s popped up in all sorts of things since.
As well as maintaining a stellar career on stage with the likes of the National Theatre, Sophie has also appeared in Casualty, Holby City and Mapp & Lucia. And to keep the Doctor Who connection alive, she’s also worked opposite Alex Kingston in ITV’s supernatural miniseries Marchlands.
Lunn – Zaqi Ismail
Relative newcomer Zaqi makes his TV debut in Doctor Who – like many young stars before him – so chances are you won’t have spotted him on the small screen before.
You might see a lot more of him soon though, as he’s due to pop up in series two of Channel 4’s period drama Indian Summers.
O’Donnell – Morven Christie
Lost In Austen’s Jane Bennet appears in Doctor Who this weekend but chances are you’ll have spied her somewhere before. The actress has played both Hero and Juliet for the Royal Shakespeare Company and was 2012’s Head of Legacy, Fi Healy.
Most recently though, she’s been starring opposite James Norton and Robson Green in Grantchester, playing Sidney’s one that got away, Amanda Kendall.
Bennett – Arsher Ali
Remember the utterly brilliant film Four Lions? Well, you’re looking at one of them. Asher Ali first rose to prominence playing Hassan Malik in the dark comedy, before going on to star as journalist Malik Suri in The Missing.
He’s also had roles in Complicit and The Guilty – plus, he’s appeared in E4’s Beaver Falls, playing Adil ‘A-Rab’ Hussein.
Pritchard – Steven Robertson
Being Human’s Mr Rook made his cinematic debut in Inside I’m Dancing alongside James McAvoy before popping up in Kingdom of Heaven with Orlando Bloom. You might recognise him as Luther’s murderous dice rolling Milberry twins and Terrence from Utopia.
Robertson has quite the TV CV, with roles in The Bletchley Circle, Shetland, Shameless and Ashes to Ashes to his name, and most recently you may have spotted him in a minor role in zombie drama In The Flesh.
Prentis – Paul Kaye
The man once known as Dennis Pennis, and Game of Thrones’ Thoros of Myr, has been no stranger to our TV screens this year. Kaye, who is also a veteran of Sharon Horgan’s Pulling, popped up in Humans and Jonathan Strange and Mr Norrell.
You might also have spotted him in Lillyhammer, Stella, It’s All Gone Pete Tong and those betting ads you see on the TV. Oh, and he’ll be appearing in the upcoming Peter Pan epic Pan too.
Neil Fingleton / Peter Serafinowicz / Corey Taylor – The Fisher King
If you’re going to make a mighty Doctor Who monster like The Fisher King then you’re clearly going to need to put in a lot of work – or hire three actors to bring it to life.
At 7ft 7in Neil Fingleton – Britain’s tallest man – provides the physique. You might have spotted him playing giant Mag The Mighty in Game of Thrones epic episode The Watchers on The Wall. Meanwhile seasoned star and veteran voice actor Peter Serafinowicz brings his Darth Maul baddie magic to the creature’s vocal chords.
And finally, the monster’s bloodcurdling scream comes courtesy of Slipknot’s Corey Taylor, who recorded his little cameo while on a tour of the Doctor Who studios.
Doctor Who Before The Flood airs on BBC1 on Saturday 10th October at 8:25pm