I was just doing a review of the show in general
And listed in it my dozen favorite episodes.
I did not include this one,
But it was close.
This to me is an episode that like some others falls just just outside that elite group.
It's a very fine episode.
The plot is good, intriguing, suspenseful, a good science fiction idea.
The characters-Really just two-Are interesting ones.
I want to know what happens to them, and Their interaction is very watchable.
The cast as usual is taken from the best that was available,
quality "character" actors when not outright stars.
Key to the show is the ending twist, And this one does not disappoint.
I'd have no problem including this one in my second dozen best episodes of the series :)