Dan is able to see a truck approaching "3 to 4 miles away". How does he do that in what appears to be a heavily wooded area? Plus we never find out what he was intending to do after he says he'll try and stop it: clearly he didn't do a very good job of it...
"Omicrom 4" is a highly-flammable liquid explosive with the somewhat nonsensical chemical equation of "C4-H7-O to the 9th". It's "very rare" but Taru can synthesize it readily!
Why does the city of Limbo maintain a very small teleport pad on the surface in the first place, particularly when they have the ability to walk through rock?
Supposedly alien planet: dynamite, a company called "Crescent Explosives".
When they are supposedly "frozen", neither Fitzhugh or Taru are very motionless...
Within walking distance: an archaeology site, including a pretty sturdy shed with telephone lines. Also, the archaeologists claim they're in a "heavily populated" area.
Joseph Ruskin, a genre veteran of many 60's s.f. shows, previously played the role of a different character in the first season episode "Terror-Go-Round".
Peter Jason is specifically credited as "Mylo" in the opening credits.
The underground set is a redress of the one used in the movie Beneath the Planet of the Apes.