Earth, which exploits the mineral resources of the asteroid belt, is the developed but fading first world, locked in a superpower rivalry with warlike Mars, while the oppressed Belters represent a colonized third world. Into this setup, the show introduced a golem-like alien substance (called, with a notable lack of imagination, the protomolecule), which across the first four seasons threatened to destroy the solar system, forcing the different factions to cooperate for their survival. In its facelessness and inexorability, it was a decent stand-in for the cylons of “Galactica.”
Fighting to save the system is, as you would expect in this sort of story, a small band of outcasts, the crew of a rogue ship named the Rocinante after Don Quixote’s horse. (The series devotes a lot of thought to the whimsical names of spaceships.) They always manage to be where the action is, largely because of a semi-mystical and narratively expedient bond between the protomolecule and their captain, Holden (Steven Strait).
The protomolecule is still around in Season 5, but a human villain moves into the foreground, perhaps temporarily, and a fair bit of time is spent early on tracking the Rocinante crew members while they scatter to take care of personal business. The show handles these plot threads with its usual efficiency and intelligence, but straying from space action and big ideas has the effect of exposing the thinness and predictability of the show’s characters. (And, perhaps, reminding you that the “Expanse” novels were inspired by a tabletop role-playing game.)
When the show isn’t showing us space battles or futuristic landscapes, with understated but evocative computer graphics, the entertainment value of its human interactions depends on the performers involved. Scenes involving the tremendously likable Wes Chatham as the warrior-like mechanic Amos are always winners, and Shohreh Aghdashloo is fun to watch as the aristocratic politician Avasarala, even though the shtick of her constant swearing wore thin a few seasons ago. Strait has a soulful quality that works well for the noble Holden. Beyond that, the performance level falls off quickly.
If you can look past some wooden dialogue and stiff acting, however, the new season might be the show’s best as an adventure-drama delivery system — the creators have only gotten better at pacing and packaging a taut conspiracy thriller over 10 weeks. Hello, “The Expanse”? Sure, why not?