Shake and Blake - Episode 23

Dave and Ian continue to make their way through the final season of
Blake's 7. In "Traitor," Tarrant and Dayna are sent to investigate
how the Federation is expanding so quickly. They discover that a
new drug and an old enemy are responsible. In "Stardrive," the crew
come to the conclusion that the Scorpio's engine sucks and decide
to get a new one. Unfortunately the one they have their eye on is
in the possession of the psychotic Space Rats and their improbable
hair. They also ask important questions like, which character had
their worst week ever between episodes? Why does the Scorpio have a
rear viewscreen? And how do you get a crash helmet over a foot-high
mohawk?