Television from the 1960's was a different animal compared to today. Actors had fewer choices as there were fewer outlets for talent back in the day.

If you were the star of a 60's TV series the assumption was "the star" got the majority of the screentime. Co-stars and guest stars got whatever was left. Dependable guest stars had to constantly make the rounds, appearing on one TV show after another. 

Part of the fun of watching TV back then was seeing a familiar guest star in a new role. 

In the 1968 Star Trek episode, The Enterprise Incident", the guest star was Joanne Linville as the Romulan Commander. She sure was an interesting love interest for Mr. Spock. They became "Secret Valentines" - you no tell!

Two aliens, devoid of human emotions, almost bring the house down with their portrial of intimacy aborad the Romulan flagship!

Shout out to Sub-Comander Tal, the coolest Romulan ever to appear on television.

Edd