Everyone’s viewing tolerance is different. Everyone has a different limit, how long she or he or we will sit through a streaming series, waiting for something — ANYthing — interesting to happen.

I got three hours into the new Amazon series “Night Sky” by first-time series creator Holden Miller before I took an irritated break to start this review.

It’s a series pitched to critics with a long string of “Do Not Reveal” edicts about its plot particulars. Here’s what they’re worried about.

This is a low-heat, flat-toned, limited effects science fiction Big Secret mystery movie whose “streaming series” stretchmarks show in every damned episode. As that’s a common complaint I have of drip-drip-drip-cliffhanger streaming storytelling, I am obliged to watch more just to see if anybody involved gets to the point, or again ANYthing interesting.

The series’ saving grace is casting Oscar winners Sissy Spacek and J.K. Simmons as an old and getting infirm/forgetful couple in small town Illinois, people who are “special” because of their secret. Tucked away in a tunnel beneath their tool shed on the outskirts of Farnsworth (the inventor of TV) Illinois is a futuristic observation room, a glimpse of the cosmus.

But what they’re about to find out is that it’s some sort of ancient portal, allowing travel in space and perhaps in time.

That’s a little vague for much of the series, as our “saving grace” couple are joined by an ever-growing crew of characters which require shifts in points of view. Among those is a younger version of Irene and Franklin.

There are plot threads that have a hint of Kurt Vonnegut about them, but the Big Secret –the series’ sole hook — is never remotely that sophisticated. The dialogue never rises up to the level of faux profound.

“I knew it was a sex dungeon” is as witty as this stiff gets.

The mother and daughter in the Argentine Andes (Julieta Zylberberg, Rocio Hernandez) are guardians of another ancient portal inside an old chapel. Well, the mother is. The daughter’s about to find out some things. Elderly Irene and Franklin’s grad school granddaughter (Kiah McKirnan) has her own story, and Irene and Franklin’s annoying and nosey new neighbor Byron (Adam Bartley) is spending too much time trying to figure out the standoffish couple next door. As I type this, another point-of-view has been introduced, that of a nursing home nurse (Beth Lacke) with a temper and a grudge.

As a stranger (Chai Hansen) pleading “amnesia” turns up in Franklin and Irene’s tunnel, it’s safe to assume his arrival and quest has a back story that must be filled in, too. First, Irene has to read a little W.H. Auden him to help him recover.

“Jude” seems not at home in this world.

All these characters, all this “mystery” and the only thing that registers are our stars and leading characters, facing a shrinking and uncertain future, grieving over what they’ve lost but still losing themselves on their trips underground to gaze upon “the Night Sky.”

In acting terms, Spacek plays Irene as curious, concerned, caring and enfeebled. Simmons’ Franklin is doting with her, crusty and standoffish with most others. That’s all well and good, but it contributes to the flat tone of this action-starved/slow-starting/characters-adding exercise in time sucking.

There’s barely a half-assed effort to “explain” what’s going on, the why and how and to what purpose. Any “tech” digressions are more to tease things out than to drive this towards “answers,” a solution and the ever-elusive conclusion.

The Argentine characters speak English in Argentina, Spanish to each other elsewhere, an example of a show with no real “rules,” or efforts to follow them.

The “payoffs” to all this start to pay off in episode five, but calling those a letdown would give letdowns a bad name. The flashbacks merely fill in little pieces of backstory and are passed along as begrudgingly as everything else in this teasing “spoiler alert” without the spoilers.

I adore Spacek and Simmons, but not enough to sit through that final two hours of “Night Sky,” expecting a miracle.

Rating: TV-14, violence, profanity

Cast: Sissy Spacek, J.K. Simmons, Chai Hansen, Kiah McKirnan, Julieta Zylberberg, Rocio Hernandez and Adam Bartley.

Credits: Created by Holden Miller. An Amazon release.

Running time: Eight episodes @:55 each.