This is the last few minutes of the last episode of Blake's 7.
It opens with the last appearance of Blake in the season two episode STAR ONE. Blake would not appear till the last episode of Blake's 7, titled "Blake."
The last episode of Blake's 7 was one of the most watched BBC episodes of all time. The ending is arguably one of the best ending for any television show. Few shows would have had the guts to go out on such a dire note.