The Expanse is a television show based on the novels by James S.A. Corey. Every week, I’ll be taking a look at one moment in each episode of the show’s second season, and chatting with the creators about how it was created and what it means for the larger story.

Spoilers ahead for the first two episodes of season 2.

The Expanse is the most politically relevant show on television right now, and it returned last night with a pair of episodes: “Safe,” and “Doors & Corners.” “Safe” picks up where we left off from season 1’s finale, “Leviathan Wakes.” In that episode, ship captain James Holden and detective Joe Miller converged: Holden and his crew were tracking down the person responsible for the destruction of their original ship, while Miller was working to find an industrialist’s missing daughter. They met on the far-flung Eros Station, only to discover that they were both after the same person, right as the station was infected with an alien pathogen that turned its inhabitants into zombies.

Introduction to Mars

But that isn’t where the show resumes for its second season. Instead, we’re greeted with a spaceship serenely flying over Mars.

The shot is reminiscent of the introduction to a Star Wars film, and effects supervisor Bob Munroe explains that it was a way to establish the second season’s new setting. Expanse viewers have heard a lot about Mars, but never really seen it. “We were looking to let the viewer first get bearings,” Munroe said, “then bring a ship into frame in order to draw us into the scene that follows.”

Our introduction to Mars comes through Bobbie Draper, the leader of a squad of Martian Marines on the planet’s surface. Bobbie was originally introduced in the second novel of the series, Caliban’s War, but the TV series often mixes elements from different novels. For instance, politician Chrisjen Avasarala, a character from a later book, played a pivotal role in the first season.

“Readers of the novels know that Bobbie plays an important role in Caliban’s War,” says producer Ty Franck, one of the two authors writing the Expanse novels as James S.A. Corey. “But for the purposes of the show, it’s difficult to introduce a brand new character halfway through a television season.”

One of the coolest parts of the episode is a long-standing trope for science fiction: power armor. “The look of the power armor came out of a combination of the description in the novels and the work of our concept designers, Ryan Dening and Tim Warnock,” Munroe says. They were constructed by Legacy Effects in Los Angeles — the same company that built the suits from films like Pacific Rim and Iron Man. The suits needed to be practical, and included a communications system and ventilation built in to keep the actors comfortable.

We meet Bobbie and her squad in a hail of bullets and explosions, during a particularly dramatic training mission on the surface of Mars — in reality, since we’re still a few years from filming in space, a parking lot. “The scene was actually filmed on a gravel parking lot next to our sound stages, bordered by a 20-foot high gravel mound on the south side,” says Munroe. (The Martian landscape was filled in later with inflatable green screens.)

“I would say that the debris and ground hits around the actors were about a 50/50 split between digital and practical. All the gunshots from the Marines, as well as the moving ammo belts [on the armor], were 100 percent digital, as were the resultant hits on targets.”

The other parts of the scenes were filmed practically. Cameras mounted on the actors helped capture an in-helmet view, while the heads-up displays in the helmets were created with digital effects.

The scene does a couple of things for the show, all in a minute and a half: it shows us Mars and its characters for the first time, but also introduces us to what its highly militaristic society is capable of. “We really haven't had the opportunity to explore the Martian worldview prior to this,” Franck says. “We touched on it in episode three of the first season, but really wanted to find chances to dig deeper in the second season.”

Attack on the Station

The rest of the first episode brings us back to Holden and Miller following their time on Eros Station. They’re taken in by rebel leader Fred Johnson, and learn where the information from the science experiment is being beamed: a space station. In episode 2, “Doors & Corners,” we’re treated to a spectacular space battle as Holden and his allies board the station.

The scene starts off with the crew depressurizing their ship, the Rocinante, as they approach the station. They’re pretending that they’re a cargo container that’s broken free of a larger ship. Once they get closer, they fire up the engines and engage the station and its defenses. The resulting battle is cinematic, and when I first saw it at New York Comic Con, it took my breath away.

“A scene like this is all about pre-visualization, and then delivering back shots that the editor can put into the cut so that we can all see how it might work,” Munroe says. “Once we have the direction, pacing, look, and tone established, the VFX facilities then take the shots to completion.”

The exterior battle was shot entirely with digital effects, cutting to practical scenes with the actors on the set of the Roci or in the landing pods, “although some interiors had digital enhancement.”

To build the gunship, the creators took cues from the novels: “It was designed to function very much like an office building — important people at the top, services at the bottom. All of our ships are designed that way. The Expanse relies heavily on real science. One way for us to achieve gravity in the show is through thrust.” The set features practical lighting and equipment, and can be pulled apart to place cameras in certain areas of the ship. When the ship takes on rounds from the enemy station, the crew used “a little bit of practical steam,” with the streams created in the ship with digital effects.

There’s a mundane start to these complicated scenes, according to Munroe. “Lots of meetings, lots of emails, lots of science, lots of rehearsal. Planning, planning, planning and more planning. And some storyboards.”

The Expanse differs from other shows in that the crew relies on a number of digital effects to create the exterior space scenes, rather than finding an existing location. “The skill of CG artists is at an extremely high level today.” Munroe says. “The experience level is fantastic, now that the industry is more mature. The technology gets better and better with every passing year. But most important, the audience demands it, so the bar continues to get set higher and higher.”

This battle is drawn right from the books, and it’s a pivotal scene that launches the action into the finale of “Leviathan Wakes.” From here, the teams learn just what the experiments are, and use that to figure out their next steps, which we’ll see in the coming episodes of the season.