The Expanse is an excellent sci-fi space opera. But it’s fundamentally a detective show.

The cases these detectives solve are the mysteries of the universe.

Every week, we pick a new episode of the week. It could be good. It could be bad. It will always be interesting. You can read the archives here. The episode of the week for June 24 through 30 is “Congregation/Abaddon’s Gate” the two-hour season finale of the third season of Syfy’s The Expanse.

The Expanse is the rare series in which the most dramatic action of an action-packed season finale involves shutting down a superweapon, not seeing what happens when it goes off. It’s ostensibly a story about humanity chasing its better angels all the way to far-off galaxies, but it’s also about how a mysterious alien species is probably playing us for chumps. I love it.

In its third season, the show’s already hectic pacing stepped up another notch. The season compressed one-and-a-half books from the series it’s based on into 13 episodes of television. And the events of those books involved near-war between humans on Earth and on Mars, then a strange mystery about a weird, ring-like structure that appeared in the far-off reaches of the solar system.

Thus, my frequent description of the show to the curious — “Game of Thrones in space” — became more literal than ever before, as the series balanced the political squabbles dominating our solar system with the much more mysterious, longer-range question of whether humanity is really prepared to take the leap to the stars to join whatever might be waiting for us.

Season three presented convincing answers to that question, both affirmative and negative. It also suggested that the one thing all intelligent life throughout the universe has in common might be an obsession with the sins of the past.

The Expanse is increasingly a series about how hard it is to let go of grievances and petty insults — on both a personal and interplanetary scale

Rafy/Syfy

When The Expanse began, a significant portion of its running time was dedicated to a detective’s hunt for a missing girl. He was from the asteroid/dwarf planet Ceres; she was the daughter of a very rich man whose entire expedition seemed to have simply vanished off the map.

This blend of science fiction and noir-infused detective drama, with a backdrop of political intrigue set in an era when human conflicts were more interplanetary than international, was clever. But it felt more like a window into a larger world than anything else, right down the detective being played by Thomas Jane, possibly the most recognizable face in the cast. It was vaguely similar to the way Ned Stark’s hunt for the truth about the death of former King’s Hand Jon Arryn powered the first book and season of Game of Thrones.

But even after Miller (the detective) discovered the girl and found that she had been killed (or, rather, remade) by a strange alien molecule (dubbed the protomolecule), even after the show had turned into more straightforward space opera, it kept returning to the idea of a central, season-long mystery holding everything together. Season two revolved around a kidnapped child, while season three’s second half was interested in the truth about the Ring, the aforementioned mysterious structure.

This focus on mystery sometimes seemed a little clumsy and forced, but the final moments of season three finale “Abbadon’s Gate” revealed that it was of a piece with what the series is about — namely the inability to escape the traumas of the past and our desire to seek resolution even when none might be forthcoming. A good detective can fill in the “what” and “how” of a crime; a great one might even fill in the “why.” But the crime can never be undone, the trauma never unfelt.

Thus, the resolution of “Abbadon’s Gate” pointed toward a long-lost alien civilization that sent the protomolecule (which eventually evolved into the Ring) to our solar system. The Ring eventually opened gates to 1,300 habitable solar systems. Humanity may have passed its test of not being so destructive that it blew up the Ring without figuring out what it did, but also seems just curious enough to almost certainly blunder through all 1,300 of those gates without being all that cautious.

The aliens, too, want to resolve a mystery. Namely, what happened to them so long ago? To do that, they need the help of another intelligent species, even if they know said intelligent species just might provoke the wrath of whatever did them in. (My working theory — without having read the books — is that it was accidental suicide. The protomolecule represents a kind of nanotechnology that disassembled the civilization on an atomic scale before anybody realized what was happening.) So humanity is given a new frontier to war over — and a new frontier to potentially destroy itself over.

The Expanse suggests that change is possible, for an individual, for a planet, for a species. But you have to really want to change, and all it takes to gum that up is one person who brings up the horrors of the past and forces you to fixate on them all over again. Maybe even with good reason! There are so many terrible things badly buried in our history books. And 200 years in the future, there will only be more.

The Expanse posits the path toward the stars not as one of peace vs. war but as forgiveness vs. cynicism

Rafy/Syfy

The back half of season three compressed almost the entirety of book three — also called Abbadon’s Gate — into seven episodes of television. (This is what I have ascertained. Again, I haven’t read the books.) That gave the episodes a slightly breathless quality, even when episode 11 of season three, titled “Fallen World,” paused just briefly enough to mourn a tragedy.

But that compression also allowed the series to bring in two big-name guest stars to play new characters who factored heavily into book three. With David Strathairn as Ashford, a former pirate who is now a respectable starship second-in-command, and Elizabeth Mitchell as the Methodist pastor Anna, the series had more star power than ever. And it cannily set up Strathairn to stand in for the side of humanity that is suspicious and afraid of the new, clinging stubbornly to the way things were, with Anna standing in for the side of humanity that embraces the future and is curious about what might be next.

This extends to the two-hour finale, which features Anna giving a speech urging a peaceful approach to the Ring, even as Ashford fires up a laser meant to destroy the structure. When his crew is briefly swayed by Anna’s words (broadcast to their ship), he mutes her to continue the mission. These two sides of humanity are not explicitly at war with each other, but for either to accomplish their goal, they have to negate the other.

Humans know, on a bone-deep level, what happens when a more technologically advanced civilization meets one with less destructive tech. Even when there’s a genuine attempt at understanding and bread-breaking, nothing good happens. So Ashford’s suspicion of the Ring makes sense. But we also know that the only way we get anywhere good involves trust and trying to work with others who are different — even if they’re a mysterious, different species from beyond the stars that might be luring us into a trap. Anna, too, makes sense.

The Expanse lives in that gray area genre fiction can occupy so well, where there are no simple “good guys” or “bad guys.” That’s usually a cliché that signals an unwillingness to grapple with difficult moral choices, and to excuse the actions of villains. But in its third season, The Expanse did nothing of the sort, instead choosing to grapple with what it means to be trapped between the forgiveness necessary to transcend the past and the cynicism necessary to make sure we don’t forget its lessons entirely.

I think often of the early days of the series when watching its later, more ambitious episodes. The protomolecule was revealed back then to have been saving the memories of the humans it consumed for fuel, then broadcasting them seemingly at random to anyone who stumbled upon the structures it was building.

As individuals, we’re simply part of some greater whole, but when broken down, when reduced to our memories, we’re also part of some greater cosmic journey toward some other version of our species. We are our memories, but also the memories of those who came before us.

The Expanse would never be characterized as “optimistic” sci-fi, as it doesn’t take place in a gleaming techno-utopia. But it is optimistic in its own way. We made it this far in the struggle within ourselves, it says. How much farther could we go?

The Expanse season three is available on Syfy’s website, with seasons one and two available on Amazon Prime. The series will move to Amazon Prime for its fourth season, debuting sometime in 2019.