The first season of Silo ended on a truly great cliffhanger. The Apple TV Plus series, an adaptation of Hugh Howey’s trilogy of postapocalyptic novels, tells the story of the remnants of humanity, who live deep underground in silos designed to protect them from a poisoned planet. Season 1 had the feeling of a small-town mystery, as mechanic-turned-sheriff Juliette (Rebecca Ferguson) stumbled upon a secret that completely upended her worldview. Her quest to uncover that mystery ultimately led her outside of the silo’s protective walls, which is right where the season ended. Silo’s second season picks up in the aftermath and ramps things up by both raising the stakes and raising a big heap of new mysteries to obsess over.

This piece contains spoilers, including details of Silo’s season 1 finale.

First, a little reminder about how we got here. The show is set at some point in the future, and the silo is home to a carefully controlled population of 10,000 residents, who follow a strict set of rules ostensibly designed to keep them safe from the grim landscape outside. That landscape is ever-present on huge displays inside the silo, and certain residents are punished by being forced to go outside, while everyone else watches as they walk out into the scorched world and, a few moments later, inevitably collapse.

But after reluctantly being thrust into the role of sheriff, Juliette learned that the outside might not be so dangerous after all. A complex series of events leads to Juliette herself leaving. But she doesn’t collapse — and her steps over the hill into a vast expanse set the silo aflame.

Season 2 picks up right in the moment when she takes those steps, and it creates two parallel threads. On one side, there’s Juliette, who learns that her home is just one of many silos. Eventually, she makes her way to a seemingly abandoned one not far from her own. The path there is littered with dead bodies; she steps over corpses and crunches a few skulls on the journey. The new silo is seemingly empty, and much of it is flooded, though somehow the power is still working. After investigating and meeting the sole survivor (played by Steve Zahn, a wonderful new addition to the cast), she quickly learns that this silo died because of a violent uprising. And what started it? Someone going outside and surviving. So despite all of the initial effort to get to this new place, she sets to work heading right back.

It shouldn’t be too surprising, then, that things aren’t going well at home. Tensions are rising as the mayor Bernard (Tim Robbins) uses every trick at his disposal in an attempt to quell a rebellion from the lower levels. Meanwhile, Juliette’s friends — spurred on by her bold steps outside — become rightfully convinced that they’re being lied to about the reality of their world. There are violent clashes on the massive spiral stairs that connect all of the silo’s levels and all kinds of clandestine meetings between different factions. The tight confines of the silo make many of these moments feel claustrophobic and intense.

What becomes clear pretty quickly is that the silos aren’t just arks meant to save humanity from a postapocalyptic wasteland. They’re also exceedingly complex psychological experiments. And those two things go hand in hand; every strange or unexpected thing that happens in the silo, it seems, is actually part of an intricate, manipulative plan to keep the population in check and avoid a deadly disaster.

That became obvious toward the end of the first season, and the complexity ramps up here. There are multiple layers of deceit and mystery, which are compounded by the fact that nobody in the silo actually knows the full picture. They’re just doing the best they can with the information they have. Even seemingly small revelations — like the quality of a certain kind of tape — can have major implications.

For season 2’s first half (I’ve watched five of the 10 episodes so far), this makes for a compelling watch that steadily expands on what made Silo so great initially. It simply expands the scale. And as the mysteries shift and grow, so, too, does the tension.

Silo’s second season starts streaming on Apple TV Plus on November 15th.