The last episode of the last series of Blake’s 7. The loss of their base on Xenon, the loss of their ship Scorpio and computer Slave, the betrayal of Blake, his death at the hand of Avon thinking Blake the betrayer, Dayna’s death, then Vila, Soolin, Tarrant, finally Avon.
Only Blake died because he had it written into his contract, so the blood. Any who wanted to return for a fifth season were only stunned, the remainder declared dead. There was no fifth season.
Only Avon survived. The Federation falls. Twenty years later he is forgotten, except by Servalan, and Travis’ daughter.