Survivors - Season 3 Episode 9 : The Enemy 1977

Charles, Jenny, Hubert, Frank and Alec arrive at a settlement based at an old coal mine. The settlement's leader, Leonard Woollen, is anxious to get the mining equipment working again and enlists Alec and Charles's help. Another man, Sam Mead (Robert Gillespie) is opposed to the idea fearing a return to the age before 'the death'. Jenny is becoming increasingly emotional about the absent Greg. Charles pushes her too far in relation to Alec...