Catharsis Factor: After a book and a half of Winston Duarte and the Laconian Empire being a borderline Invincible Villain, suddenly the aliens who wiped out the protomolocule creators finally get good and pissed off at him and remove much of his advantage out of existence in a split second. The remainder of Tiamat's Wrath is the heroes getting sweet payback for all the indignities heaped on them.
Complete Monster: Marco Inaros, from Nemesis Games and Babylon's Ashes, is the leader of the Free Navy. When he was younger, Marco tricked his girlfriend, Naomi, into helping him sabotage ships' magnetic bottles, allowing him to destroy any ship he wants without any sign of foul play. When Naomi protested this, Marco forbade her from seeing their son, Filip. When Naomi left him, Marco raised Filip to believe that Naomi was a weak-willed coward who abandoned him out of spite. Marco uses Filip to help carry out an asteroid bombardment of Earth that kills 15 billion people. While Marco claims to be fighting for his fellow Belters, he nearly destroys a large chunk of Tycho Station just to kill Holden for dating Naomi, and cripples Ceres Station through looting just to slow down his enemies. Marco justifies his crimes against the Belters by claiming that they weren't "true Belters", but it quickly becomes apparent that Marco defines true Belters as only those who are personally loyal to him.
Crazy Awesome: In Nemesis Games, a power-armored Bobbie Draper surfs on a laser-guided missile to save a free-floating Naomi drifting in vacuum.
Chrisjen Avasarala and Bobbie Draper are popular with a lot of readers. The former as one of the few politicians in the series actively working to improve the situation and refusing to take shit from anyone. The latter for her snark, badass Action Girl status, and more or less getting to be a space marine in an otherwise gritty series. In the show, the two are even added to the events of books they weren't present in, Leviathan Wakes for Chrisjen and Abaddon's Gate for Bobbie.
Samantha Rosenberg, aka Sam is one of the most popular side characters. Snarky, helpful to the protagonists, and an all around Nice Girl who gets some of the best lines. It's a real shame she's killed off in Abadon's Gate.
This character is largely the origin of OPA member Drummer (see the note for Ensemble Dark Horse in the TV show below), though her role in the TV show is vastly expanded with her rising in the OPA to become Fred's right-hand woman and getting most of Bull's scenes and plot relevance from Abadon's Gate - and she gets Spared by the Adaptation for both her Sam's death and Bull's.
Fridge Horror: After Marco's attack on Earth halfway through Nemesis Games, what happened to the characters we last saw either living there or headed there for other reasons? Basia's daughter? Anna's wife and daughter? Havelock? One or more of them might have been off-world for any number of reasons, but if they weren't, the situation doesn't look good.
Thankfully, Anna and her family are all revealed to be alive in the next book. No word on anyone else though.
Holden's moralistic attitude grates on some readers' nerves, but the only character who really strays into this territory is Elvi Okoye from Cibola Burn. Readers and professional reviewers alike often call her a one-note character whose Celeb Crush on Holden comes out of nowhere, is way over the top in terms of shoolgirl-like behaviour, and is resolved by a coworker man-splaining her own emotions to her and telling her You Need to Get Laid. Which she immediately does, with the man-splainer, who had had a crush on her for some time; and then she apparently falls in love with that guy within a few days. Yeah... Not one of the authors' most feminist moments...
Despite the Character Development and the Freudian Excuse of being raised by a complete narcissistic sociopath, a lot of readers still can't find anything redeemable about Filip Inaros. Being the person who orchestrated the near-destruction of Earth will do that.
Woobie, Destroyer of Worlds: Clarissa Mao. By the time she joins up with the Roci crew, she's been through the proverbial wringer, and it's implied she still has nightmares. Having as much blood on her hands as she does, she may never fully come to terms with herself. As of Clarissa's death in Persepolis Rising she still hasn't, although she has gained the forgiveness and trust of the rest of the crew. The implants she intended to use to kill Holden—and which are in turn killing her in the long run—she uses to save him and his companions in a final sacrifice.
The more initially antagonistic relationship between the members of the Rocinante, especially in comparison to their book counterparts. While many fans have stated that they feel it was a necessary change so as to add more interpersonal drama aboard the Roci and make the show more interesting for a television audience, others have complained that it just comes across as ultimately contrived and makes it harder for the audience to see why the crew would even work together in the first place.
The decision to have the "Slow Zone" look more like an alien nebula rather than the starless black void described in the books. Some have described it as more visually interesting and a sensible change so as to better differentiate the region from the "normal" Sol System, while others have complained that it looks uninteresting and loses the more alien emphasis upon the region from the book series. Amusingly, the swirling alien appearance of the TV version of the Slow Zone is exactly what it looks like come the events of Tiamat's Wrath after the aliens unleash the exploding neutron star.
Cargo Ship: Alex literally breaks up with his wife so he can stay with the Rocinante.
Catharsis Factor: Although "Immolation" is still a super-tense episode, it does allow for some excellent catharsis. All of the primary villains get their comeuppance, and it's immensely satisfying to watch. The vilest of them all, child-torturing Strickland, begs for his life before Amos rightly puts him out of everyone's misery with a 12-gauge to the head. Errinwright is revealed for the manipulative extremist he is and arrested. Nguyen is left to die in a mess of his own making. And Jules-Pierre Mao is taken prisoner by Holden and delivered right to the feet of his old enemy, Avasarala...who, for bonus points, is wearing his daughter Julie's flightsuit from the Razorback, symbolically allowing the now-dead Julie to be present to condemn her father's misdeeds.
The warmongering UN Admiral Augusto Nguyen seeks to use protomolecule hybrid super soldiers to wipe out Mars and its seven billion inhabitants. When Admiral Souther attempts to relieve Nguyen of command for his acts of treason, Nguyen murders Souther and several officers loyal to him. When a few UN ships refuse to obey Nguyen's orders, Nguyen decides to make an example of the fast-attack boat UNN Jimenez. Nguyen fires on this ship himself after the CIC watch refuse to fire on a friendly ship. When a damaged hybrid-carrying pod crashes into the UNN Agatha King, Nguyen is mortally wounded. He uses his last moments to mock Alex and Naomi for trying to stop him, making it clear that he is motivated purely by racism against Martians.
Dr. Lawrence Strickland appears to be a kindly pediatrician who treats children with a rare spinal condition. In reality, he is a scientist studying the protomolecule for the Protogen Corporation. Strickland discovered that children with the spinal condition he specializes in treating can be transformed using the protomolecule into controllable super soldiers called hybrids. Strickland kidnaps his patients, many of whom trust him like a father, infects them with the protomolecule, and turns them into hybrids to be sold to fight in wars. When Katoa, one of Strickland's protomolecule-infected patients, brutally murders a nurse on orders from the protomolecule, Strickland is fascinated and accelerates the protomolecule's infection of Katoa to interrogate him, only stopping when the protomolecule completely overwrites Katoa's mind. When the crew of the Rocinante come to stop Protogen, Strickland sends the now fully-hybridized Katoa against them as a distraction, leading to Katoa's death. In a last ditch effort to save himself, Strickland murders his remaining nurse and tries to pass himself off as another of Protogen's prisoners.
When the Arboghast is "deconstructed" by the protomolecule on Venus in "Caliban's War," everyone has an initially terrified Oh, Crap! realization...Well, except for Iturbi, whose shit-eating grin at being proven right about the existence of extra-solar life makes the scene (somewhat) darkly hilarious.
MCRN Lieutenant Lopez underwent such rapid character-development that it made him very likable and memorable despite only appearing in two episodes.
After casually executing two of her previous captors while having a bullet lodged in her stomach in "Pyre", OPA member Drummer became a fan favorite. As a result, her screentime and plot relevance is vastly expanded in the TV show compared to her book-counterpart (Samantha Rosenberg), she gets many scenes that were part of Bull's plotline in Abbadon's Gate (instead of Sam's function in the plot of that book, which is given to Naomi and a mauve shirt OPA member), and she even survives Bull's death scene from the book.
Klaes Ashford, having been a particularly unlikable antagonist in Abbadon's Gate, has turned into a fan favorite as well. Unlike his book counterpart, Ashford in the series is a competent, respected leader who doesn't let politics get in the way of common sense, and has a greater vision than most of the OPA leadership except perhaps Fred Johnson.
It also helps that he gets parts of Bull's characterization and plot from the booksnote Bull was wisely edited out for the TV show, given that he was basically just Miller 2.0, or how Miller would have been if somebody saved him from his alcoholism and gave him the home / group-belonging he was desperately longing for. To further clarify, Bull's scenes were reassigned to Ashford and Drummer., doesn't start out as the ship's captain, and gets a new backstory as a space pirate who tragically lost a child.
More "Morally Ambiguous Is Sexy," but Amos (being played by Wes Chatham) is very good-looking for a near-sociopath. Bobbie Draper also initially falls into this category, though it's later inverted upon her HeelFace Turn in the second half of Season 2.
Melba/Clarissa Mao is quite beautiful for a psychologically unstable murderer and saboteur.
Inverted with Holden and Naomi, who are probably the two members of the Rocinante with the most "acute" senses of right and wrong, and are both played by the attractive Steven Strait and Dominique Tipper.
With the revived Battlestar Galactica, what with both series being (relatively) hard sci-fi Space Operas that give a fundamentally cynical and philosophical analysis upon humanity as they progressed into the stars.
With Game of Thrones. In fact, a very popular turn of phrase when The Expanse first started to get significant critical acclaim was describing it as Battlestar GalacticameetsGame of Thrones.
Genius Bonus: In Season 4, Amos is shown trading bullets for drinks. An apocryphal story says that, in the Old West, a single bullet could be bartered for a small portion of whiskey leading to the term "shot of whiskey" and the "shot glass".
Growing the Beard: Season 1 was critically acclaimed, but Season 2 is where the show became significantly bolder and the plot became more intricate, with the characters becoming significantly more interesting and well-developed as consequence. Amusingly enough, this was also around the time the series got the cred for being able to use the occasional Precision F-Strike (albeit censored, muffled, or replaced with "forget you" on some broadcasts) to better match its characters to the ones in the books. Season 3 introduces the Belter Creole equivalent 'felota', which allows the writers to get away with a lot more than in previous seasons (at least for Belter characters—Drummer and Ashford make copious use of it in particular).
While his performance was never seen as necessarily bad, Steven Strait's performance as Jim Holden was often seen as being the comparative "weak link" out of the Rocinante crew. However, his surprisingly captivating depiction of someone undergoing rapid Sanity Slippage in "It Reaches Out" was widely praised and seen as some of his best work on the show.
Wes Chatham's performance as Amos Burton has been one of the most consistently praised aspects of the series, with his genuinely convincing depiction of a near-sociopath attempting to find a moral compass being both surprisingly engaging, genuinely unsettling, and weirdly endearing. Many fans have even favorably compared his "I am that guy" line from "Immolation" with "I am the one who knocks!"
While initially seen as just an unlikable jarhead, Frankie Adams as Bobbie Draper got a much better reception as Season 2 went on and she was able to show more of her own impressive acting range beyond the generic "tough guy" marine persona originally shackled to her.
Hilarious in Hindsight: Over a private dinner, Chrisjen Avasarala states after learning of the protomolecule's extrasolar origins that the idea of aliens existing is completely terrifying as they are unequipped to handle them if they are a threat. Fans may find this hilarious as Chrisjen's actor, Shohreh Aghdashloo, played a similar authority figure character in another science fiction franchise who was herself an alien.
Naomi and Drummer have copious amounts of sexual tension from the moment they start bonding during "Static." When Naomi leaves the Behemoth, it's treated very similarly to a break-up, leading fans to speculate. Season 5's "Winnipesaukee" removes any ambiguity from Drummer's side, at least: when Drummer is talking to Oksana while believing that Naomi is dead, she explicitly refers to her as "a woman that I loved". Oksana then asks if Drummer loves her and the rest of their crewmates (who are all in a (polyamous) relationship with each other) as much as she loved Naomi, which Drummer affirms.
Ambiguously Bi Tilly Fagan has a fairly flirty relationship with canonically gay Anna.
Magnificent Bastard: While Sadavir Errinwright begins as a pawn for Mao, when Mao turns on him, Errinwright shows how skilled a manipulator he is. Errinwright assassinates Mao's Martian contact and starts a war between Earth and Mars to force Mao to work for him. Seeking to use Mao's protomolecule hybrid supersoldiers to give Earth the strength to conquer Mars and remain secure, Errinwright begins a campaign to undermine the Secretary General's anti-war speechwriter Anna, first convincing her that her actions allowed Mars to kill millions in South America and then altering a speech she wrote to call for the annexation of Mars. Errinwright is ultimateley undone when Avasarala accomplishes the almost-impossible task of obtaining a copy of a message between Errinwright and Mao and sends it to Anna. When Errinwright realizes that he's lost, he calmly admits to his crimes and remains dignified as security takes him away.
Memetic Badass: Drummer, who many fans have openly claimed is only kept from single-handedly conquering the entire universe by her loyalty to Fred Johnson. Her badass reputation only increased after she built working mechanical legs/prosthetics for herself and continues to kick ass in the Season 3 finale.
One of the OPA refugee ships coming from Ganymede in "Pyre" takes all the people from Earth and Mars and throw them out of the airlock.
Jules-Pierre Mao crosses it in "Assured Destruction" when he backs up from his HeelFace Turn and agrees to keep experimenting on the children. The scientists doing the experimenting themselves, including Dr. Strickland, also count here.
Admiral Nyugen's cold-blooded murder of long-time colleague Admiral Souther and his subsequent slaughter of the other mutineers in "Triple Point", all so he can commit genocide against Mars.
Melba/Clarissa Mao wades into this when she blows up a UNN supply ship and frames Holden for it in an attempt to get him killed. Interestingly deconstructed though, in that she's extremely conflicted about her actions (both before and after pressing the button) and ultimately pulls a HeelFace Turn in the season finale, saving the entirety of humanity in the process.
Avasarala callously uses her son's death for political gain in a speech full of Crocodile Tears to make herself more relatable. Arjun is naturally furious about it and says they should separate shortly afterward. And she even loses the election anyway, making it All for Nothing.
Marco Inaros wants more rights for Belters and wants the Belt to become its own superpower that's no longer oppressed by the "Inners". This would be a noble goal if he didn't take insanely extreme methods to try to assert control: he uses Martian stealth technology to drop numerous asteroids onto the Earth, killing millions of innocent people, threatens to unleash the protomolecule onto Earth and/or Mars if either of them defy him, and claims that all of the Ring Worlds now belong to Belters, essentially making him far more of a tyrant than the Inners ever were to Belters.
Jonathan Banks appears for all of three minutes in the pilot episode, playing a man suffering from Space Madness, and milks every moment for all it's worth.
Veteran character actor Daniel Kash only really has one scene as head protogen scientist Dr. Antony Dresden (excluding a Season 1 cameo toward the end via a recording) but he is highly memorable and deeply chilling in his portrayal of someone who truly believes the ends justifies the means. Even after all the horrors he's wrought, he somehow manages to make the promise of what the protomolecule can do not only vital, but strangely attractive. It's little wonder that Fred and Holden almost immediately start to become convinced by the sheer passion and logic of his argument.
The scenes with Manéo Jung-Espinoza in "Delta-V" ultimately aren't very long, but Zach Villa's surprisingly endearing performance and his memorablyhorrific death have made it nearly impossible to forget him.
Some fans found Bobbie Draper to initially be incredibly annoying for her frequent gun-ho behavior on the Earth/Mars conflict, viewing her personality as largely flat outside of this trait. However, after the Ganymede disaster, learning about Mars' experiments, and getting a healthy dose of Character Development, Bobbie began to convince non-book fans that there was more to her character, and has now become a fan favorite.
Klaes Ashford went from being a largely unlikable and unsympathetic mutineer in the books to an incredibly likable Reasonable Authority Figure in the series, to the point that some fans have argued that he honestly might actually be a better fit for the captain of the Behemoth than Drummer.
Elvi Okoye was The Scrappy in Cibola Burn due to her over-the-top Celeb Crush on Holden that gets resolved too quickly. When adapting this novel into Season 4, the show wisely does away with this; instead, Holden and Elvi start off not completely seeing eye-to-eye, but gradually gain increasing respect for each other and become Fire-Forged Friends as they work together to save everyone on Ilus, culminating in Elvi playing a very important role in the climax. All throughout, their camaraderie remains completely platonic on both sides, and Elvi instead gets Ship Tease with Fayez (the guy she rather-suddenly ends up with in the books). As a result, she is much less annoying and more likable in this version.
Sacred Cow: In part after the "#SaveTheExpanse" fan campaign which successfully got the series Un-Cancelled, this attitude has started to seep into the fandom.
The Scrappy: Come Season 3, Diogo Harari has become very unsympathetic and his once-amusing self-delusions have turned him into an infuriating Smug Snake.
On a more spoiler-ridden note, Miller meeting with Julie Mao for one last time on Eros at the climax of "Home" and Chrisjen's epic Badass Boast in "Paradigm Shift" are often held up as two of the best moments in the entire series.
When walking up to the Belter undergoing gravity torture in "Dulcinea", Chrisjen bizarrely shrinks as she goes from the left of the screen to the right, indicating that they were shooting on a forced perspective set.
Minor case, but most of the more complex Belter tattoos are pretty obvious decal tats. The one on Drummer's neck is just the most prominent example, and it gets especially grating in Season 3 due to the large number of Belters on the Behemoth.
Downplayed since the series is already based on a book series. That said, some fans favorably compared the series to the Honor Harrington novels, especially in regards to the main similarities in how their long-term world building, political maneuvering and progressive technological developments that dramatically alter the military and political landscape are utilized within the narrative.
The show already has a video game adaptation of sorts. It's called Call Of Duty Infinite Warfare which has the exact same plot of a United Nations-dominated Earth fighting a rebellious force of space colonists who want to break away from the government and form their own nation.
Squick: As with the books, virtually anything to do with the protomolecule, though special mention probably has to go to Katoa's "disassembly" of his nurse in "Reload."
Take That, Scrappy!: After becoming an insufferably arrogant and idiotic Jerkass throughout Season 3, Diogo Harata gets a vicious verbal and physical beatdown by Ashford before having an elevator dropped on him by Naomi in "Abbadon's Gate."
Tear Jerker: Has its own page, though special mention must be given to when Miller finally meets Julie face-to-face in "Home" and he prevails upon what's left of her humanity to steer Eros away from Earth.
They Wasted a Perfectly Good Plot: Some fans were disappointed with the mid-Season 3 Time Skip that shifted the show's focus to the Ring, as they felt that not only were the intervening events (i.e. the uprooting of the Protogen conspiracy) on both Earth and Mars) interesting enough to watch in their own right, but also that trying to then stuff all of the third novel into just half a season left that material feeling rushed as well.
The effects used for the spaceships and space battles are pretty cool to look at, but the opening sequence for episode 1 (and the entirety of Season 2) deserves special mention. It shows the progress of humanity over the next two hundred or so years and is simply gorgeous.
The inside of Eros after the protomolecule has fully taken over in "Leviathan Wakes" is truly a sight to behold, and it gets ever more gorgeous the closer Miller draws to its core.
The fate of the Arboghast, which takes a seemingly simple shot and turns it into something intricately beautiful.
The climax shot of Caliban's War where The "Caliban" Protomolecule creature is crawling over the hull of the Rocinante is just breathtaking.
The show is generally amazingly good at making the audience believe that characters are floating in Zero G whenever she ships aren't under thrust and the characters couldn't lock down to the floor with magnetic boots. Case in point: the forced-slowdown situation in the Season 3 episode "Fallen World".
WTH, Casting Agency?: Arjun Avasarala was recast for Season 4, with Michael Benyear replacing Brian George, who was unavailable. The differences are so striking that essentially nobody realized they were meant to be the same character, and Benyear makes no attempt to emulate George's performance. Benyear looks completely different from George, uses a different accent, plays the role a little more coldly than George's warm portrayal, and is much younger than either Brian George or Shoreh Aghdashloo. It inadvertently ends up looking like Chrisjen just ditched her first husband for a boytoy between seasons.
WTH, Costuming Department?: The show uses off-the-shelf rank insignia and applies them haphazardly and inconsistently. So a yacht captain wears the insignia of a US Army sergeant major while MCRN captains' insignia change from episode to episode and Gunnery Sergeant Draper wears the same stripes as an MCRN lieutenant.
Woobie, Destroyer of Worlds: Melba/Clarissa Mao might be a villainous saboteur and murderer, but she's clearly unwell and suffering for her father's sins. She's tormented by her actions, but feels she's come too far to stop now, and we get a good view of how abysmally she was treated by her own father.note Whereas in the book, it was implied she was "Daddy's darling" or at least not The Unfavorite. Furthermore, Anna immediately likes her instead of realizing "This woman wants to kill me" just from looking into her eyes the first time they met, which helps give Melba more moral ambiguity as consequence. Also, given that we don't get her narrative POV and self-justification thoughts in the TV show, she comes across as far less of a sociopath than in the first half of the novel-version of Abbadon's Gate.