Ying Ki – Marlowe Chan-Reeves
Madam Ching – Crystal Yu
Chief Sea Devil – Craige Els
Ji-Hun – Arthur Lee
Ying Wai – David K.S. Tse
Sea Devils – Jon Davey, Simon Carew, Chester Durrant, Richard Price, Mickey Lewis, Andrew Cross
General production staff
Head of Production – Charlotte Bloxham
Executive Producer for the BBC – Ben Irving
Production Executive – Tracie Simpson
Line Producer – Steffan Morris
Associate Producer – Sheena Bucktowonsing
Production Manager – Delmi Thomas
Supervising Location Manager – Iwan Roberts
Location Manager – Gareth Roberts
Location Assistant – Tom Chalkley
Unit Manager – Kyle Yates
Production Co-ordinator – Sandra Cosfeld
Assistant Production Co-ordinator – Ellie Simmons
Production Secretary – Sam Milletti
Executive Assistant – Caroline Cook
Production Office Runner – Ellie Hilton
Unit Drivers – Paul Watkins, Jolyon Davey, Steve Darwent
Unit Medics – Glyn Evans, Andy Jones
Business Affairs – Roger Leatham, Elaine Evans, Kyle Parsons, Steve Robson
Production Accountant – Rhys Evans
Assistant Accountants – Kate Barber-Williams, Marta Toczko, Elise Betts
Cast Payroll Accountant – Helen Searle
Contracts Booker – Leanne Bowcott
Crew Payroll Accountant – Bethan Wray
Covid Assistants – Joseph Fletcher, Lloyd Di Mauro
Covid Testing Schedulers – Etty Stanley, Leila Arada
Camera and lighting department
1st Assistant Directors – Christopher J Thomas, Elaine Mackenzie
2nd Assistant Director – Lauren Pate
3rd Assistant Director – Jennifer Day
Assistant Directors – Jac Lewis, Laura Thompson, Tom May
Script Supervisors – Abdoulie Mboob, Amanda Lean
Camera Operator – Mark McQuoid ACO
Camera Trainees – Adam Clewes, Olga Walus
Focus Pullers – Jonathan Vidgen, Matt Hillier
Key Grip – John Robinson
Assistant Grips – Matt Clark, Marc Marshall
Camera Assistants – Nic Yates, Evangeline Davies
Gaffer – Mark Hutchings
Rigging Gaffer – Andy Gardiner
Best Boy – Gareth Sheldon
Electricians – Gawain Nash, Stuart Gale, Matthew Hutchings, Rhodri Moses, Owen Hashimi
Art department
Supervising Art Director – Ifan Lewis
Construction Art Director – Julia Jones
Art Department Assistant – Laura Honeybun
Art Department Co-ordinator – Hannah Miller
Production Buyer – Billie Blue Williams
Petty Cash Buyer – Sally Sharp
Set Decorator – Vicki Male
Action Props Buyer – Milannah Faith Summers
Concept Artist – Chris Phillips
Graphic Designer – Stephen Fielding
Trainee Graphic Designer – Lois Drage
Standby Props – Ryan Milton, Robert Alexander
Standby Carpenter – Colm Garrett
Prop Hands – Dewi Thomas, John Thomas, Liv Cheung, Tom Major, Jodie Gibson
Standby Art Director – Cerys Lewis
Rigging – Shadow Scaffolding
Standby Rigger – Alex Herbert
Scenic Painters – Alison Drane, Rachel Willsher, Alex Morgan, Ana Marlene Ribeiro
HOD Painter – Scenic Steve
Painter – Mark Reece
Storeman – Lucy Hookings
Prop Master – Paul Aitken
Props Chargehand – Trystan Howell
Props Driver – Paul Carmichael
Construction Manager – David Hobbs
Construction Assistant – Matthew Pike
Workshop Manager – Mark Hill
Workshop Assistant – Chris Slocombe
Construction Chargehands – Dean Tucker, Jonathan Tylke
Construction Driver – Darren Bousie
CNC Programmer – Kristian Tucker
Plasterer – Jason Tylke
Practical Electricians – Rob Hearne, Matthew Dunford
Draughtspersons – Lauren Harper, James Dyer
Trainee Draughtsperson – Rachel Ellis
Carpenters – Chris Daniels, Campbell Fraser, Matt Gronow, Charlie Wright, Marcus Scholl, Ben McDonald, Dafydd Llewelyn Jones, Mike Venables, Gemma Spence, Simon Pothecary, David Warner
Costume department
Costume Supervisor – Grace Brooks
Assistant Costume Designer – Simon Marks
Costume Cutter/Maker – Brighde Penn
Creature Costume Maker – Robert Allsopp & Associates
Costume Assistants – Ian Fowler, Jenny Tindle, Michelle McGrath
Costume Trainee – Yiwen Lin
Make-up and prosthetics
Make-up Supervisor – Amy Riley
Make-up Artists – Angharad Walsh, Diana McDonald, India Jones
Junior Make-up Artist – Nikki Salih
Movement
Stunt Co-ordinators – Crispin Layfield, Belinda McGinley, Derek Lea, Andy Godbold, Stephanie Carey
Movement Coach – Paul Kasey
Stunt Performers – Anna Benton, Donovan Louis, Isky Fay, James Pavey, Louis Samms, Robert Pavey, Rob Jarman, Tom Hatt, Varpu Kronholm
Casting
Casting Associate – Ri McDaid-Wren
Casting Assistant – Ray B├╢hm
General post-production staff
Post-production Producer – Ceres Doyle
Post-production Supervisor – Liv Duffin
Assistant Editors – Brooke Taylor Michael, Joseph Keirle
On-line Editor – Christine Kelly
Special and visual effects
Additional VFX – Martyn Western, Rory Williams, Zodiak VFX, Ben Pickles
VFX Editor – Emily Lawrence
Assistant VFX Editor – Jacob Percival
Colourist – Gareth Spensley
Head Model Maker – Lee Radford
Model Makers – Penny Howarth, Lee Price
Sound
Sound Recordist – Deian Llyr Humphreys AMPS
Dubbing Mixers – Natasha Haycocks, Howard Bargroff
Sound Maintenance Engineers – Christopher Goding, Joe Malone
Sound Designer – Harry Barnes
Dialogue Editor – Darran Clement
ADR Editor – Matthew Cox
Foley – Bang Post Production
The Doctor and Yaz encounter the Sea Devils, an ancient aquatic alien race returning to reclaim EarthΓÇÖs oceans. Alongside pirate allies, they investigate a lost Chinese treasure ship. The Sea Devils attempt to activate an ancient weapon. The Doctor stops their plan, but the encounter deepens her awareness of YazΓÇÖs growing feelings for her.
The Doctor and her companions travel to 19th century China, encountering pirates and maritime legends.
The Sea Devils are aquatic reptilian humanoids returning to reclaim the oceans from human interference.
Zheng Yi Sao appears as a powerful pirate captain allied with the Doctor.
The Sea Devils plan to unleash destruction on humanity, believing humans have damaged the natural world.
The episode explores environmental balance, history, and cooperation between cultures.