The Doctor attempts to persuade Captain Hart of the danger that the Master represents. Eager to make contact with the Sea Devils, the Doctor journeys deep into the ocean.
Share this with
See all episodes from Doctor Who
See all clips from Episode 4
See all broadcasts of Episode 4 (2)
For the latest news, photos, videos and more, follow us on:
Find out what the TARDIS has on file about Missy/The Master.
Create and play your own amazing adventures in time and space!
Available on: DVD or Video download
From suppliers including: BBC Store
Where to buy
See all galleries from Episode 4