Missy – Michelle Gomez
The Master – John Simm
Jorj – Oliver Lansley
Surgeon – Paul Brightwell
Nurse – Alison Lintott
Voice of the Cybermen – Nicholas Briggs
General production staff
Head of Production – Gordon Ronald
Production Executive – Tracie Simpson
Line Producer – Steffan Morris
Production Manager – Adam Knopf
Location Manager – Iwan Roberts
Unit Manager – Beccy Jones
Production Co-ordinator – Sandra Cosfeld
Assistant Production Co-ordinator – Nicola Chance
Production Assistants – Virginia Bonet, Paige Woodward, Jamie Shaw
Unit Drivers – Paul Watkins, Jolyon Davey
Unit Medic – Glyn Evans
Business Affairs Executive – Carol Griggs
Production Accountant – Simon Wheeler
Assistant Accountant – Matthew Fisher
Camera and lighting department
1st Assistant Director – Dan Mumford
2nd Assistant Director – James DeHaviland
3rd Assistant Director – Christopher J Thomas
Assistant Directors – Rhun Llewelyn, Lauren Pate, Kieran Hayhow
Script Supervisor – Nicki Coles
Camera Operator – Mark McQuoid
Focus Pullers – Jonathan Vidgen, Elhein De Wet
Grip – John Robinson
Assistant Grip – Sean Cronin
Camera Assistants – Gethin Williams, Drew Marsden, Chris Jacobi, Dan Patounas
Gaffers – Mark Hutchings, Andy Gardiner
Best Boy – Gawain Nash
Electricians – Gareth Sheldon, Bob Milton, Sion Davies, Andrew Williams
Art department
Supervising Art Director – Dafydd Shurmer
Art Director – Tim Overson
Art Department Accountant – Bethan Griffiths
Production Buyer – Jen Saguaro
Set Decorator – Adrian Anscombe
Prop Buyers – Jo Pearce, Charlotte Lailey de Ville
Storyboard Artist – Mike Collins
Concept Artist – Sam Lamont
Graphic Artist – Christina Tom
Standby Props – Matt Ireland, Jonathan Barclay
Standby Carpenter – Paul Jones
Prop Hands – Nigel Magni, Faith Summers, Tom Leaman
Standby Art Director – Nick Murray
Rigging – Shadow Scaffolding
Standby Rigger – Colin Toms
Head Scenic Artist – Clive Clarke
Painters – John Nelms, Steve Nelms, Paul Murray, Tara McCourt
Storeman – Matt Watts
Prop Master – Paul Smith
Props Chargehand – Scott Howe
Props Driver – Gareth Fox
Construction Manager – Terry Horle
Construction Chargehand – Dean Tucker
Construction Driver – Jonathan Tylke
Construction Labourer – Jason Tylke
Practical Electricians – Callum Alexander, Austin Curtis
Graphics Assistant – Jack Bowes
Draughtsperson – Matt Sanders
Carpenters – Tim Burke, Keith Richards, Matt Ferry, Campbell Frazer, Chris Daniels, Joe Painter, George Rees, Dan Berrow, Tom Berrow
Title Concept – Billy Hanshaw
Costume department
Costume Supervisor – Gayle Woodsend
Assistant Costume Designer – Elizabeth Richards
Costume Assistants – Rebecca Cunningham, Leila Headon, Jenny Tindle
Make-up and prosthetics
Make-up Supervisor – James Spinks
Make-up Artists – Megan Bowes, Lolly Goodship, Derek Lloyd, Cathy Davies
Movement
Stunt Co-ordinators – Crispin Layfield, Derek Lea
Stunt Performers – Troy Kenchington, Andrew Burford, Freddie Mason
Choreographer – Ailsa Berk
Casting
Casting Associate – Ri McDaid-Wren
Casting Assistant – Louis Constantine
General post-production staff
Post-production Supervisor – Samantha Price
Post-production Co-ordinator – Hannah Jones
Assistant Editor – David Davies
On-line Editors – Geraint Pari Huws, Christine Kelly
Special and visual effects
VFX Editor – Dan Rawlings
Special Creature Effects & Prosthetics – Millennium FX
Colourist – Gareth Spensley
Model Makers – Alan Hardy, Jamie Thomas
Sound
Sound Recordist – Deian Ll┼╖r Humphreys
Dubbing Mixer – Mark Ferda
Sound Maintenance Engineers – Tam Shoring, Christopher Goding
Dialogue Editor – Darran Clement
ADR Editor – Matthew Cox
Sound Effects Editor – Harry Barnes
Foley Editor – Simon Clement
Foley Artist – Julie Ankerson
The Doctor answers a distress call from a colony ship near a black hole, where time moves differently across its levels. Bill is shot and converted into a Cyberman. The Master, in disguise, is revealed to be behind the events, alongside Missy. The Doctor faces the devastating consequences of his trust and the return of old enemies.
The Doctor responds to a distress call from a colony ship caught near a black hole, where time dilation causes different parts of the ship to experience time at drastically different rates.
One floor of the ship experiences time far faster than the others, meaning characters age and develop over decades while only minutes pass elsewhere.
The episode reveals the early creation of Cybermen through the experiments of John Simm Master and the conversion process taking place on the lower decks.
Bill Potts is tragically converted into a Cyberman, marking one of the most emotional turning points in the series.
The episode explores time, identity, suffering, and the ethics of survival under extreme conditions.
