Blake's 7 (1978)

S2E7 Killer

In the episode "Killer," the crew of the Liberator travels to a planet to assist Avon's acquaintance in acquiring TP crystals. During their mission, they come across the abandoned ship K-47, which they bring aboard. However, they soon discover that a dangerous virus harbors within the ship, leading to a rapid outbreak throughout the entire facility. As the crew grapples with the spreading infection, tensions rise, and they must find a way to contain the threat before it escalates further.