The Fifth Doctor, Tegan and Turlough arrive on Sea Base 4, a nuclear warhead station under the sea that has some very nasty neighbours.
The Doctor
Tegan Jovanka
Vislor Turlough
Vorshak
Nilson
Solow
Bulic
Preston
Maddox
Karina
Paroli
Icthar
Scibus
Tarpok
Sauvix
Seabase Crewmember
