Worm Star is set in a big galaxy where humanity has spread out in a huge, archaic empire. Everything is overly bureaucratized and running in sheer inertia; They borrow a lot of pomp from nobility tropes. Crowns, gold, gems, tasseled uniforms, everyone having four or five titles, blatant nepotism.
The main character is an astonishingly handsome blue-haired prince, immensely wealthy and powerful, who is charged with restoring order in a 'lost sector' infested with pirates and rebels. He's charming and determined, leading several battles against a recurring 'pirate king', where orchestral music plays and people in fancy uniforms shout at each other about missiles and armor and damage control over exploding computer consoles in between CGI shots of the ships fighting. The pirate king talks about how the empire isn't wanted here, and newly 'liberated' planets aren't happy to be conquered back, because the Empire's laws and police are rather brutal. One of the prince's subordinates actively hides just how bad it is from him, knowing the prince is a 'bleeding heart' who'd disrupt things trying to help people.
After the first few big battles there's negotiations with the local planetary governors and industrial magnates for new ships and supplies, and the prince and his guards have a running gunfight through a rusty frontier city trying to catch a female assassin who murdered a merchant he was trying to make a deal with, which ends in a damaged cable car riding a huge black ribbon up off the planet; The assassin falls, but unbeknownst to the prince, manages to survive with a personal parachute. The prince is disquieted by this and asks for reinforcements from his father, but is told that actually he needs to send some of his ships back because of unspecified trouble back home.
The prince decides to go directly after the pirate king, wrongly thinking he's the source of all the problems. The chase leads them to several fantastical worlds with distinct climates and architectural styles - a tan desert planet, a chilly frozen planet, an ocean-covered water planet, all of which they have gunfights, vehicle chases, or swordfights in. They encounter the assassin several more times, but the prince sees her leaving her targets to save children. Later, she tells him that the merchant she killed liked to kidnap and torture women. The prince admits he admires the assassin's determination to do what's right, but they each have their duties and cannot be together. Then he tries to capture her, but she gets away again.
The climactic battle is a chaotic fight in a dense asteroid field, with hidden ships and mines all around. The pirate king's base is an old forgotten colony ship, beautiful in abandoned grandeur. Just as the prince is lining up for the killing blow, the assassin contacts his ship! She begs him not to fire on the old colony ship, since there are innocents in cryo-sleep in it! The prince has to make a harrowing decision - kill the pirate king and restore order to support the Empire, but also kill hundreds of thousands of innocents and ruin a wondrous piece of lost technology... Or let the pirate king get away to continue making trouble across dozens of planets.
He decides to let the pirate king get away. That's when his subordinate tries to kill him and take over the ship, and there's a dramatic mutiny and room-to-room fighting! The prince looks on his subordinate with shock and shame, the subordinate says that the prince's father would be disappointed in him. The prince has the traitor locked up, and then takes control of the ship, but by now the pirate king has gotten away. The last few scenes are him talking to the assassin, betraying the empire on the reasoning that it's only making things worse by being so brutal and restrictive, and establishing a new free-market republic with the colony ship, even as the empire dissolves into civil war.
All the music is, of course, extremely dramatic and impressive-sounding, and the costumes and props are top-notch in terms of artistic detail. All the empire technology is artfully intricate and lavish, and all the frontier technology looks ruggedly reliable. The pirate king's scummy-looking outfit and comically irreverent antics and banter were well done too, Alex thinks.