"Silo."

The Apple TV+ sci-fi series gets the Two Episode Test.

I think my pronouncements on previews — avoid them if you can — are pretty well known now and certainly solid. That said, I do break that rule more often than I’d like.

I mean, I watched the “Drops Of God” trailer and thought, “Oh, no, definitely not” and then loved the pilot. (Still waiting for my wine guru Dan to return from Europe to watch the rest together if possible). And fairly recently — probably by watching “Drops of God,” I saw the preview of “Silo” and, yeah, watched it. I mean, it’s not a crime. It’s just a general rule that you’re better off not watching.

But I watched. And the preview worked, because then I watched the show. I’m pretty sure that’s exactly how they drew it up on Promotions.

What really happened is even better. I saw the preview and then mentioned it to my partner, KB, who flipped out (sci-fi nerd) and said that she’d read the books (The “Wool” series that was famously self-published by Hugh Howey). I mean, of course she did. Right in her sci-fi loving wheelhouse. I, on the other hand, had never even heard of “Silo” (she thinks “the Silo series” was added to the “Wool” books?) and was thus unable, as usual, to freak out excitedly.

My partner also doesn’t have Apple TV+ so, yeah, I was not allowed to jump ahead. But here’s the beauty of that — and it’s a thing that I haven’t really been able to imagine myself experiencing in, I don’t know, decades: I played the preview for her and she was instantly swept up, then again as the title rolled, exhilarated that what she’d imagined in her head (the allure of a novel) was now so vividly come to life. In fact, in the first episode it was hard for her to contain herself actually seeing what the silo looked like, how the world made in print and come to life in her brain was now being visualized by Apple TV+ and Graham Yost (“Justified” etc.) who created the show for TV and wrote the pilot episode (only two have dropped — the third is tonight, followed every Friday with another).

I was a little jealous to not be transported — I mean, what, the last time a book I can remember loving got made into something I was desperate to see on the screen was…Watership Down? Who knows. Despite that, and despite not having read the books myself, I too was immediately hooked by the lavish production qualities and visual “feel” of “Silo.” The post-apocalyptic world translated almost instantly. That, you probably don’t need to be reminded, is no easy feat. To feel immediately immersed in something that you believe is real, that tangibly looks like your mind might imagine such a place and the production design pulls you in at every decision — color, lighting, scale, architecture, etc.? Rare.

But will it hold up?

“Silo” is exactly what it sounds like — a long tube with 144 floors (and no elevator) that houses what is essentially left of a post-apocalyptic world on Earth, drilled into the ground and sealed. People have been down there for a long, long time. Outside is death. Inside is not. That’s basically their lives. The people are celebrating 140 years of “Freedom Day” where they put down a rebellion that was going to open the upper hatch doors to the outside world. It was foiled. So everyone lived. You can see the irony of the concept of both rebellion and freedom.

What made “Silo” an immediate hook was that initial visual panache that allows your brain to travel to this space and believe it exists, to be curious about what it looks like, the spaces inside, the secrets that are hidden. It also helped that Yost, who made this world happen along with director Morten Tyldum, is masterful at the introduction of the mystery of the silo itself and each individual character. The ability to take something that’s complex — and will likely be more comprehensively dense soon enough — and give it a layer of simplicity that doesn’t seem like pandering or ineptitude is impressive. You never doubt that “Silo” knows what it’s doing and where it’s going, even though it moves back and forth in time almost from the start and gives viewers a — chef’s kiss — seamless simplicity.

I don’t know how to state that more emphatically. While KB was geeking out on the look of the show and announcing the names of characters before they were spoken on screen, I was simultaneously fully engaged (without having read the book) and didn’t feel behind her or lacking in details. Look, it’s only two episodes but I can’t remember being in combination with someone viewing a show who was dying to see it and knew everything about it and yet, within minutes, I felt well-versed in the world and who the players were, too.

You’ve probably guessed by now that “Silo” passed the Two Episode Test with ease. And that’s directly related to Yost and Tyldum nailing their jobs with ease. “Silo” feels like it has some gravitas to its world — not the flimsy and sometimes silly way that a lot of sci-fi shows announce themselves. Tyldum captures not only the hulking presence of the silo — it’s massiveness, its spinal columns and strange floors, screwing down from top to bottom in cylindrically creative displays (a floor for animals, farming floors, living quarters, shared spaces for eating and gathering, the sweaty lower levels that run the silo, etc.), but also its intimacy. In the same way another sci-fi series (with a much lower budget), Battlestar Galactica, was able to make the cramped metallic rooms feel personal and intimate (in fact, the whole ship was, much like “Silo,” instantly defined), the set here allows a weird kind of modernist pod to evoke the bedrooms of the people in the silo. It feels futuristic but you never forget that it’s basic, either — as children acting as porters race up and down the circular spine (child labor being OK, apparently), and there’s a mechanical grime to it all. In effortless detail “Silo” shows you that its interior isn’t as uniform as you might guess.

There’s a lot of steps. Better wear your Apple Watch and use the Fitness app.

I’m purposefully keeping plot details sparse here, since A) there’s not much to know yet other than people in the silo believe anyone outside of the silo is dead and B) Yost and the writers are not trying to be coy — as a viewer you’re encouraged to speculate that everybody in the pod is either in an experiment or brainwashed and there’s a world outside that works, some how, some way.

Without naming characters, two people in the first two episodes break the cardinal rule of life in the silo — they say, out loud, “I want to go out.” After that, your fate is sealed. You’re arrested and given your wish and everyone inside gets to watch you walk outside in a space suit and eventually crumple to the ground. Your dead body (in the space suit) is then on display forever, right outside the cafeteria window, as a kind of warning to be careful what you wish for and don’t challenge the norm.

Rebecca Ferguson, Rashida Jones, David Oyelowo, Common, Tim Robbins, Will Patton and Geraldine James make up the front end of a solid cast here.

I talk a lot about setting the hook and keeping viewers around — something that can be done in a variety of successful ways, depending on the show. What “Silo” does right almost immediately is familiarize you with a world you can guess at and give you characters who are intriguing. Without wasted effort, Yost presents the very beginning of what you know will be a complicated story and does it in an uncomplicated, engaging way. If the set design and visuals are the first triumph of the series, it’s also reassuring to know that good dialogue and nuanced characters seem to prop up the visual allure quite well in the first two episodes. It gives you faith. It make you want to keep watching.

What more is there, really?