- Jodie Whittaker (The Doctor)
- Mandip Gill (Yasmin 'Yaz' Khan)
- John Bishop (Dan Lewis)
Episode: Season 9 Prologue
Air Date: 2015-09-11
Runtime: 2 min
The Doctor visits the planet Karn, to discuss an old enemy...or is it an old friend? 'and embarks on a course that could lead to his destruction....