I just listened to the Blake's 7 radio adventures that consisted to two audio dramas. Great to hear most of the cast together.
The Sevenfold Crown involved Servalan trying to get hold of an artifact that would allow her to take over the galaxy. Avon wants it too.
The Syndeton Experiment. The crew look for the inventor of a chip that allows total control.
Each "episode" was about an hour long and there was a further hour of interviews, which i also enjoyed. I definitely want to listen to more, but i don't want to sign up to a subscription service. I might look at the Big Finish dramas and down load a few next week.