Blake's 7 (1978)

S3E7 Children of Auron

Servalan unleashes a devastating plague on the inhabitants of Auron, prompting the crew to race to Cally's native planet for a rescue mission. Meanwhile, Servalan cleverly manipulates this crisis to lure the Liberator into her clutches, intending to create clones of herself—her only potential heirs whom she believes she can rely on.