Planet Earth

With Marc Daniels directing, William Theiss doing costumes, and Bob Justman producing, this is about the Star Trekkiest non-Trek this side of TNG: no less than seven people who directly worked on Star Trek TOS.

Essentially a sequel/revamp of Genesis II, reusing the premise, the bullet-train sets and even the p.o.v. Shot of the zooming tunnel. Ted Cassidy and Majel Barrett return -- Ted as the same character, Majel as slightly different one (though barely seen). Janet Margolin capably replaces Lynne Marta as the plucky Harper-Smythe.

As is usual for these fictional female-dominated societies, there's little logic applied and apparently no research into actual female-dominated societies, so we can forget the "science" part of "science fiction" and just call it fantasy. The good news is that the actresses largely pull it off: Sally Kemp particularly brings a feeling of naturalness to her character Treece, though that may partly owe to the fact that hers is the most realistic role. Diana Muldaur's role is tougher, as she has to embody the dumbest aspect of the plot, but she does it well.

The overall result is adequate. I wouldn't tell anyone to make an effort to see it, but honestly John Saxon makes almost anything look good. Notable non-Roddenberry move: for Muldaur's final scene, they gave her a close-fitting red dress with a neckline that plunged to her navel .... and then only showed her from the side, from a great distance, or from the neck up. Women's lib indeed.