This episode features a gold eating monster called Goldon. It also has a rather greedy miner, or perhaps he is just overcome with gold fever. It's never really explained where the Goldons come from- yes, there are two of them, though we never see both in the same shot.
I'm sure that was a cost saving device. It's also an episode where you feel sorry for the monster, as it was pretty much minding it's own business until people show up and disturb it.
Since it's an episode that's set underground- well, about half of it is- Ito invents a new machine called, appropriately enough, the Pellucider. The reason for this name should be well known to anyone reading Edgar Rice Burroughs' "Pellucider" series.
It's never easy to show a machine moving through the ground in any kind of format, what with the ground being solid and all. They do a pretty decent job here. It's used to rescue the miner who discovered Goldon.
Ito also equipped the machine with a laser and some rockets, which come in handy when the second Goldon attacks them.
This time it's Fuji's turn to suffer some head trauma, as she is knocked down the mountainside. Head wounds do bleed a lot, even if they aren't deadly. But that's a lot of blood for a kid's show!
Ultraman does defeat and kill the monster, which is then disemboweled or something, so the miner can have his gold and the town can be rebuilt. Yeah, it's kind of a sad end to the beast.