They're the actual fourth race, but we never see them, ever. Season 10's "200" has a great joke about them.
"Torment of Tantalus" is generally regarded as one of the finest episodes of the first season, and I mostly agree. It seems you didn't like it quite as much as the majority of the fandom, but yeah, it's not bad at least.
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K | H | A | Q | Q | A | H | K
"we're about 50 years behind the rest of western society." -icon on B8