Visitors from Beyond the Stars - S1.E18

The guys land in a Western town in the late 19th century, where they are intercepted by two silver-clad aliens. The two aliens need to steal protein to supplement their own supplies, and soon use their advanced technology to mind-control Doug and hold the confused townspeople at bay while stealing local cattle. Tony manages to get hold of one of the alien control devices. Meanwhile, at Project TickTock the same alien race but from 1966 arrive and demand to know what happened to their scouting party a hundred years earlier, believing the Project to have something to do with it. Tony manages to free Doug from mind control and defeat the aliens in the past, while the ones in the present witness the departure of the scouting party in the past and are satisfied Earth had nothing to do with their disappearance.