Torchwood S01 E06 Countrycide

"Save the Planet (One Alien at a Time)"

Whilst investigating a group of unexplainable deaths in a village, the Torchwood team are separated. Discovering further, Jack, Gwen and Owen find a scared man, hiding from the thing responsible for the murders. But Tosh and Ianto go that one step extra, and locate the killer, who wants them as their next victims.