The Expanse Season 1 Is A Different Genre To The Book It's Based On

Published Sep 13, 2026, 3:00 AM EDT

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The Expanse's debut season has previously been described as 'Game of Thrones in space,' and while you'll be disappointed if you're expecting dragons and scenes you wouldn't want to watch with your parents in the room, there's logic behind the comparison. Just as Game of Thrones is an action-heavy fantasy series and a political thriller with Westeros as its battleground, The Expanse is an action-heavy sci-fi series and a political thriller with the Sol system as its battleground.

The Expanse is a little more faithful to its source material, especially in its latter seasons. Whereas HBO's series increasingly distanced itself from George R. R. Martin's books, The Expanse arguably became even more book-accurate as it progressed, and would follow its 'one novel per season' formula more precisely from season 4 onward.

As such, it's surprising that one of the biggest differences between The Expanse and James S. A. Corey's original books is that season 1 exists within a different genre compared to Leviathan Wakes, the first novel in the series.

Because The Expanse season 1 carefully toed the line between its sci-fi storyline with James Holden, its detective storyline with Joe Miller, and its political storyline with Chrisjen Avasarala. Holden holds down the space exploration elements, making his way from destroyed ship to destroyed ship like a bad penny. Miller does his noirish investigator-in-love shtick, digging up clues and moping. Avasarala, meanwhile, heads up the show's political front, jostling with rivals and conducting diplomatic warfare as manipulative sharks emerge from all corners of the system.

To put it another way, Holden is Jon Snow, Miller is Tyrion Lannister, and Avasarala is Olenna Tyrell.

Between the three of them, The Expanse season 1 becomes a sci-fi murder mystery political thriller mashup, but the same description cannot be applied to Leviathan Wakes.

That first book has the sci-fi and murder mystery bases covered, but the political back-and-forth so prominent in season 1 is largely absent. For starters, Avasarala doesn't appear in The Expanse's first book at all, and neither does her friend-turned-adversary, Sadovir Errinwright. Throughout season 1, The Expanse's political storyline is effectively told via those two characters, so without them, the first book is only slightly more political than Paddington Bear.

The struggle between factions happens mostly in the background of Leviathan Wakes, recapped by Miller after he watches newsfeed updates. The true negotiation table sparring between Earth, Mars, and the Belt comes in later books, and that first entry is much more of a fast-moving blockbuster than the slow-burn tension seen in The Expanse's first live-action TV season. Likewise, the nuance and complexities of inter-Belt faction dynamics are explored in later books, once the series moves beyond using Holden and Miller as perspective characters.

The Expanse Book 1 Also Has More Horror Influences

Another notable genre difference between The Expanse season 1 and Levithan Wakes is the latter's greater (albeit still subtle) reliance on horror influences. On TV, the protomolecule is depicted as a glowing blue, very science fiction-y substance that wouldn't look out of place in Star Trek. When Holden and Miller first encounter the protomolecule in Leviathan Wakes, however, it's described as a brown sludge, and the text describing its effect on Julie Mao's body is so graphic, the scene as written could have never been adapted authentically.

The body horror continues when Holden's crew investigates the ship Julie was held on, the Scopuli. As in the TV series, the Scopuli's reactor has been covered in protomolecule. In live-action, this is shown as a network of glowing blue spores. In the books, it's described as a mountain of mangled body parts, with visible limbs and bones from dead crew members clinging together in a fleshy mash that sounds more reminiscent of The Thing than anything seen in The Expanse's TV adaptation.