“All Will Be Revealed” the on-air tease promised at the end of last week’s two-hour “Under the Dome” premiere, offering an incentive to brave another visit to the hermetically sealed-off town of Chester’s Mill. And while certain facts did come spilling out in rather ungainly fashion, either that ad was misleading (hardly a shock in the world of network promotion) or the words “all” and “revealed” must mean something different in TV circles.

It’s worth remembering only a few weeks have passed, in actual time, during the two-plus summers the show has been airing on CBS, seeking to wrangle Stephen King’s book into a manageable series. As with many past King productions, the mystery-shrouded premise reeled in viewers initially, only to watch those big numbers erode as the program became increasingly frustrating in its absurdity.

Until now, the producers have done a pretty fair impersonation of Lucy with the football, pulling it away from poor Charlie Brown every time he tried to kick it. So Thursday’s episode (and SPOILER ALERT if you haven’t watched) did notably advance the story, but also left as many perplexing questions as it answered, perhaps especially for those trying to watch without the benefit of having absorbed King’s 2009 novel.

After a strange flight of fancy to kick off the season, characters emerged from strange cocoons, in which they experienced extraordinarily real-feeling visions. The big reveal, such as it was, is that confinement represents part of some alien plot to control these hapless humans, being presided over by the newly arrived Christine (Marg Helgenberger), who has told the townsfolk that she’s a therapist seeking to help them, but who in fact is an anthropologist doing the aliens’ nefarious bidding.

“We’ve hatched and we’re under a dome?” asks Christine’s sidekick, Eva (Kylie Bunbury). “None of this makes sense.” See? Everyone really is a TV critic these days.

Obviously, the producers can’t dump everything into the open in one burst, and network marketing gurus have a knack for, shall we say, turning the snippets afforded them into lemonade; still, these revelations were hardly satisfying – providing no details about, say, why a malevolent alien force would place a dome over the town (particularly this town), given the resources presumably at their disposal. What once had the potential to be a cool “The Twilight Zone”-like scenario — testing how puny earthlings behave under pressure, a la “The Monsters Are Due on Maple Street” — drifted away on a pile of red herrings and the gossamer wings of all those glowing butterflies.

Although the ratings have dropped, “Dome” started at such lofty heights that it’s still a relatively robust performer by summer standards, especially in light of CBS’ Amazon deal and international sales. Even so, the steady audience decline no doubt indicates a sizable percentage of viewers became fed up with the show, something that seems unlikely to be remedied by its latest twists.

Thanks to the aforementioned factors, “Under the Dome’s” creative shortcomings alone might not undermine its commercial viability, but the third season nevertheless offered another chance to smooth over some of the program’s rough edges. Yet while the inhabits of Chester’s Mill remain in peril, after the opening chapters of season three, without the promise of finality and closure that would come from an announced end date, it’s going to be hard, frankly, to give a dome.