S2E20 Return to Tomorrow

Original Air Date 2/9/68

The Enterprise discovers three discorporate intelligences who seek their help in gaining physical bodies... but one of them has plans of his own.

This must have been the one you were talking about, Dizzle, with the 'seeders.' I really enjoyed this one.

It was pretty funny watching Shatner rub his hands all over his body when the alien took him over, too bad Mulhall didn't doo the same Speaking of Mulhall, she was played by Diana Muldaur who also played Dr. Miranda Jones in "Is There in Truth No Beauty" and Dr. Pulaski in TNG. I knew about Dr. Jones, and obviously Pulaski, but didn't remember this role until I saw her and heard her voice in this episode!

This was indeed the one. As I'm watching more and more.. I just watched TAS S1E8 The Magicks of Megas-Tu, I'm beginning to realize just how for granted Star Trek takes the impossibility of any truth to any religion beyond explaining alien interactions at best. I love it. I'm surprised there aren't nut jobs boycotting the movies like there are anti-Harry Potter people.