Tonight, Syfy will begin the third season of The Expanse, its science fiction series based on the book series by James S.A. Corey. The novels debuted in 2011, and the television adaptation, which followed in 2015, has become one of the most timely and politically relevant stories on television. Over the past two seasons, it’s teased a coming war between the system’s various nations, and how the crew of a stolen warship, The Rocinante, plays its own role in navigating the troubles.

The show returns tonight at 9 PM ET / 8PM CT, and it’s worth checking out. Here’s what you need to know to get caught up.

Warning: Spoilers for previous seasons of The Expanse, and some of the novels, ahead.

Photo by Rafy / Syfy

What the show is about

The Expanse is a science fiction story set two centuries from now. Humanity has colonized the solar system, and as a result, three rival factions have sprung up: citizens on Earth, colonists on Mars, and a coalition of settlements in the asteroid belt and moons near Jupiter and Saturn called the “Outer Planets Alliance.”

When an ice-hauling ship is destroyed, it kicks off a chain of events that bring the factions to the brink of war. The crew of a ship called the Rocinante investigate the burgeoning conflict — which they discover may actually be a carefully engineered attempt to cover up the discovery of a mysterious alien substance called the “protomolecule.”

Photo by Rafy / Syfy

Why you should be watching

Science fiction often imagines what the future of humanity might look like. Star Trek imagined a utopian society that boldly goes into the cosmos in the search for understanding, while Battlestar Galactica took a realistic look at what people do to survive during a crisis. The Expanse has a nuanced and sometimes cynical view of where we’re headed: it’s a show about power and the consequences of its misuse, and how divisions in society are detrimental to everyone.

That may sound all too similar to real-world problems, but The Expanse‘s uncanny ability to let viewers re-examine our crises through a fictional lens is what makes the series so compelling. The show is richly resonant, touching upon modern concerns like xenophobia and racial resentment, while at the same time its multiracial cast offers a refreshing look at the kind of diverse future that is inevitably humanity’s future — even while many of the people in the show’s fictional world are looking backward.

It’s science fiction with purpose and a point of view, but also with impressive production values, especially around its space battles.

Photo by Rafy / Syfy

The characters you need to know

The show mainly follows the crew of the Rocinante: Captain Jim Holden (Steven Strait), pilot Alex Kamal (Cas Anvar), engineer Naomi Nagata (Dominique Tipper), and mechanic Amos Burton (Wes Chatham), who come from all parts of the system. They want to track down the people responsible for engulfing the system in a war. In the first two seasons, they’re aided by Fred Johnson (Chad Coleman), an Outer Planets Alliance leader who runs a space station called Tycho; a scientist named Prax (Terry Chen); and a detective named Miller (Thomas Jane).

There’s also Chrisjen Avasarala (Shohreh Aghdashloo), the UN Assistant Undersecretary of Executive Administration, a foul-mouthed bureaucrat who’s trying to protect Earth and keep it from entering a bloody conflict. She ends up at odds with her superior, Sadavir Errinwright (Shawn Doyle), who is working with the people responsible for the protomolecule.

Finally, there’s a Martian marine named Bobbie Draper (Frankie Adams), who defected to Earth after her soldiers were killed by a new breed of protomolecule weapons.

Where season 3 begins

During season 1, the crew of the Rocinante wound up in the middle of a giant conspiracy to kickstart a war. In season 2, they went after its perpetrators, an evil corporation called Protogen, while Bobbie ended up working with Avasarala to try to de-escalate the larger conflict. The season ended with the Rocinante’s crew on Jupiter’s moon Ganymede, desperately trying to track down a Protogen researcher as a battle between Earth and Martian forces broke out around them.

That’s where season 3 will kick off: with the threat of more protomolecule weapons and a looming, solar-system-wide conflict.

Art: Orbit Books

What the books tell us about what’s next

So far, the show has covered the first novel in the series, Leviathan Wakes, and half of the second, Caliban’s War. While there have been some changes, the series has largely tracked the biggest story moments from the books, so it’s likely that showrunner Naren Shankar will draw upon some of the remaining high points from Caliban’s War for the new season. That makes it likely that Avasalara, Bobbie, and the crew of the Rocinante will meet up and join forces to try and stop the brewing war. But the biggest untold part of the story is what’s going on with the alien protomolecule.

Midway through season 2, the substance hijacked an asteroid and crashed it onto Venus, where the protomolecule began building… something. The end of Caliban’s War reveals that it was creating a massive stargate, which then flew to the end of the solar system. The fight for control of the gate is the focus of the third book, Abaddon’s Gate, and elements of that book’s plot, and the stargate reveal, will likely appear in the TV season to come.

How to catch up on the series

If you haven’t seen the show yet, there are a couple of ways to catch up. The first two seasons of the show are now available for streaming on Amazon Prime in the US, while they’re available internationally on Netflix.

Cable subscribers will be able to stream new episodes through Syfy’s website, and they’ll be available for purchase on Amazon, Google Play, and iTunes as well.

https://www.theverge.com/2018/4/11/17225472/syfy-the-expanse-science-fiction-television-catch-up