The Lights Of Zetar: (Episode 73)

Strange-colored light entities take possession of Lt. Mira Romaine, Scotty's new love. If Kirk can't exorcise these Zetarians, they'll kill Romaine and the U.S.S. Enterprise crew.



The Cloud Minders: (Episode 74)

Suspicious Troglytes, subservient miners on the planet Ardana, refuse to give zenite to Kirk and his crew. Without this antidote, billions will die on a Federation planet.