On Basilisk Station consists of a prologue, 32 chapters, as well as a short appendix on Honorverse timekeeping.
At a cabinet meeting, Havenite Hereditary President Sidney Harris is informed that the People's Republic of Haven is about to go bankrupt due to its poor economy and overblown Naval budget. He and his advisors consider conquering one of the wormhole junctions on their borders, and soon agree that the most worthy prize would be the small but wealthy Star Kingdom of Manticore.
Commander Honor Harrington of the Royal Manticoran Navy is shuttled to the space station Hephaestus with her treecat companion, Nimitz. She is greeted by her new executive officer, Lieutenant Commander Alistair McKeon, and taken to the bridge to assume command of the light cruiser HMS Fearless. She is informed that half her ship's armament has been removed to install an experimental weapon called a "Grav Lance", a fact she was not made aware of before.
Commander Harrington retreats to her cabin to study the ship's books and the recent "refit". Realizing that her new command is a pawn in the theoretical dispute between conservative and progressive schools of military tactic in the Admiralty, she becomes angry, but vows to do her best to make the Grav Lance work in the upcoming war games.
Pitched against Admiral Sebastian D'Orville in the war games, Honor is able to sneak up on the "enemy" force and take out D'Orville's flagship, scoring a victory in the first round.
After Admiral D'Orville and his captains looked through Honor's tactic, Fearless was "destroyed" in all following thirteen rounds of the war games. As a result, crew morale is low. Honor dines with her officers, spending some time evaluating each of them. At the same time, Lieutenant Commander McKeon is irritated by his own feelings of envy and dislike towards his captain.
Some time later, Honor receives orders to proceed to Basilisk Station, an underdeveloped duty station in the star system of the same name, which contains the Manticore Wormhole Junction's most recently discovered entry and exit point. It is a well-known "dumping ground" for undesirable officers.
After passing through the wormhole to the Basilisk System, Fearless is instructed to rendezvous with HMS Warlock in orbit of the planet Medusa. Honor is so horrified when she learns that the ship is commanded by Lord Pavel Young that even Commander McKean realizes that something is wrong.
Honor makes her way aboard Warlock to report to Captain Young, who coldly informs her that he will have to return his ship to Manticore for repairs shortly, and dismisses her. Honor recalls how he tried to rape her in the shower at the Naval Academy on Saganami Island years ago when they were both cadets, and how she beat him up and decided to stay silent out of shame and fear of his noble father's influence. Deciding that she will not let him ruin her career, she leaves.
Back aboard Fearless, Honor informs her officers that they will soon be the sole RMN vessel to guard Basilisk Station. She orders Lieutenant Andreas Venizelos to select thirty-five ratings and a junior officer for detachment to Basilisk Traffic Control, while engineering is to prepare reconnaissance drones to create a sensor network in the system. Commander McKeon advises to have the drones power up only once every half hour in order to make them last longer, the first active contribution he ever made to Honor's plans. When Lieutenant Venizelos suggests to requisition additional drones from Captain Young, Honor refuses without explanation.
Captain Michel Reynaud of the Manticore Astro-Control Service is shocked when Lieutenant Venizelos reports to him as the new customs and security officer, explaining to the young officer that no former CO of Basilisk Station ever bothered to actually assign anyone to him.
While her crew works on ways to make the recon drones work properly, Honor reviews the system's geography and is annoyed by the presence of a Havenite courier boat in orbit of Medusa. She requests to be connected to Resident Commissioner Estelle Matsuko.
Once in Matsuko's office, Honor is greeted warmly and informed that the Havenites have established trading posts to interact with the Medusans, the native race of sentient non-humans on a bronze-age level of civilization. Under current law, Matsuko can do nothing about that, as she only has jurisdiction over Manticoran merchants. She also tells Honor about a dangerous local drug called mekoha that seems to have become a lot more widespread since the arrival of humans on the planet. Matsuko also assigns Major Barney Isvarian of the Native Protection Agency to Harrington as a liaison.
Major Isvarian informs Honor and Lieutenant Commander McKeon how thinly stretched the NPA has been, and the captain agrees to assigning more crew and resources to its operations. She also asks her Bosun to find crew members who are "familiar" with how to hide contraband on a ship to man the customs flights.
When Commander Lois Suchon, the ship's medical officer, complains about the reassignment of her assistants to other duties, Honor reprimands her and voices her suspicions that Suchon's main concern is that she might actually have to do some work herself. Being the daughter of two doctors, one of them an officer himself, Honor knows exactly what a medical officer's duties are, and that Suchon has not been doing hers.
Meanwhile, Lieutenat Venizelos begins his customs inspections of the freighters present in the system, and soon encounters resistance from a Havenite merchantman. When the young officer makes it clear that the RMN will enforce the law by the letter from now on, the civilian relents.
Other crew members begin to become more engaged as well. Ensign Prescott Tremaine and one of his noncoms, Horace Harkness, inspect the Manticoran freighter Mondragon. They soon discover that the ship's crew is smuggling Kodiak Maximus pelts with a total worth of 43 million dollars, and the vessel is impounded. When Lieutenant Commander McKeon points out that this might get them all in trouble with the trade cartels back home, the captain brusquely tells him that they will do their duty no matter what.
Some time later, back on Manticore, First Space Lord Admiral James Webster and Admiral Hamish Alexander meet to discuss Commander Harrington's recent actions. Webster has received a total of 14 official protests from merchant houses since she became senior officer at Basilisk. When Alexander asks why Captain Young has not been called out for abandoning his post under false pretenses, the First Space Lord points out how powerful Young's father, the Earl of North Hollow, is. Also, Klaus Hauptman, head of the powerful Hauptman Cartel and owner of the Mondragon, is violently protesting the seizing of the ship.
In the end, as the local Basilisk officials are singing her praises, the two admirals decide to leave Harrington in place.
The Fearless crew is busy with gunnery exercises when Honor is screened by Commissioner Matsuko, who informs her about a number of unidentified flights in restricted areas on Medusa. Suspecting that this has something to do with the mekoha drug trade, which is now available in a more potent form, they decide to investigate further.
Denver Summervale, a disgraced Manticoran marine and distant cousin of current Prime Minister Allen Summervale, Duke of Cromarty, is informed by a mysterious contact that the NPA has found out about the new mekoha. He ponders the consequences for his illegal operations, and thinks about the life that led him to his current job; after taking money as a paid duelist to pay his debts, he was dishonorably discharged from the Marine Corps.
Wallace Canning, the Havenite consul on Medusa, meets with an unnamed admiral. They discuss the secret laboratory that has been built to produce mekoha, and how to keep it hidden. The admiral mentions that Operation Odysseus is well underway, and that they might be able to use the fact that Honor Harrington's parents are employed by Duvalier Medical Associates, a subsidiary of the Hauptmann Cartel, against her. The admiral then departs for Manticore.
Petty Officer Harkness proposes to Ensign Tremaine that they should change the flight plans of their boats so their sensors can help scan the planetary surface. Tremaine agrees.
Meanwhile, chief engineer Dominica Santos informs Commander Harrington that she does not have enough data for a detailed analysis of the surface power usage on Medusa. Honor then summons McKeon and acting tactical officer Rafael Cardones, and tells them to analyze the power usage. The executive officer seems unhappy with the idea, but complies. After he has left, Santos tells Honor that she has known him for a long time, and that he deeply loves the Fearless. In the end, he will not let her down.
Technician Hiro Yammata discovers a drain on the Medusan power network 62 kilometers west-southwest of the Muddy Wash Valley, and informs Ensign Tremaine. Commissioner Matsuko soon dispatches Major Isvarian with a raiding party. However, when they try to enter the lab they find in the target location, they are attacked and the building is destroyed by a huge explosion. Lieutenant Tremaine's pinnace goes after a fleeing aircar and destroys it with its laser gun.
Matsuko is shocked by the 55 dead and six wounded the NPA suffered in the incident, and deduces that someone must have warned the people running the lab. She also informs Honor that one of the NPA troopers, Matt Howard, was killed by a flintlock rifle designed for Medusans, but obviously not constructed by Medusans: somebody from off-world is supplying the natives with deadly weapons.
Lieutenant Venizelos is informed by Captain Reynaud that a courier boat with Klaus Hauptman aboard is incoming from Manticore.
Consul Canning asks Havenite Army Colonel Bryan Westerfeldt what went wrong at the mekoha lab. They discuss that Summervale has disappeared after blowing up the site, and that the Medusans seem to be replicating the guns they were given. Canning then orders Westerfeldt to hide with their Medusan contacts until Captain Young and the Warlock return to Basilisk.
Meanwhile, as Denver Summervale leaves the planet on a Silesian freighter, Lieutenant Commander McKeon learns of Klaus Hauptman's arrival, and goes to inform his captain. Honor orders her marines and NPA ground force officers to formulate a response plan against an attack by a flintlock-armed native uprising.
The Manticorans realize that someone has been tapping their own power net to produce mekoha and sell it to the natives. At the same time, Honor is contacted by Klaus Hauptman, who asks to see her in person. She invites him aboard, but Lieutenant Commander McKeon advises against seeing him alone. Honor dismisses his concerns, but McKeon insists on being present as a witness, and she eventually accepts.
Honor greets Hauptman aboard Fearless, and escorts him back to her briefing room. Once there, he demands that she stop "harassing" his ships, and even threatens to use his company's influence to ruin her parents. At that point, Lieutenant Commander McKeon intervenes, and informs Hauptman that he will testify before a court of law that the civilian just threatened a Queen's officer and her family in order to make the Royal Manticoran Navy abandon its responsibilities on Basilisk Station. He also mentions that the equipment used to redirect power to the drug lab was built by Hauptman, and that a case could be made to accuse the Cartel of acts of treason against the Star Kingdom. Honor follows up by telling Hauptman that if he should ever move against her family in any way, she will demand satisfaction on the field of honor.
After Hauptman has left, Honor and McKeon finally discuss the personal problems the exec seems to have with his new commander. McKeon summarizes that he projected his own feelings of insecurity on her because she rose through the ranks even though she is younger than him, and apologizes for letting her and the ship down. Honor accepts, and the two promise to work together better from now on.
At the ancestral seat of the White Havens, Admiral Alexander talks to his younger brother, William, the Star Kingdom's Lord of the Exchequer. They discuss the ramifications of Commander Harrington's actions, and the growing outrage caused by Klaus Hauptman's influence, which has actually led to the Basilisk problem being scheduled to be addressed in Parliament. The Prime Minister wants exactly that to happen, so Alexander asks his brother (unofficially, of course) to make sure that the Warlock is not repaired in time for Captain Young to return to Basilisk and take command back from Harrington.
After contacting James Webster, Admiral Alexander meets with Vice Admiral Craig Warner, commander of the space station Hephaestus, who happily agrees to delay Warlock's refit in order to inconvenience a North Hollow.
Two days later, Honor contemplates recent developments: Commissioner Matsuko has had an interview with a courier from Countess New Kiev, the Minister for Medusan Affairs, in which she angrily told the Ministry to back off from the Navy's operations in Basilisk. The tap on the power collector has turned out to be a dead end, and the actions of whoever is operating on Medusa continue to destabilize the situation on the surface.
Honor and her senior officers discuss how to use their ground forces in case of an attack by the Medusans.
Lieutenant Samuel Webster, Fearless' communications officer, delivers a message to Honor that Captain Young's recent request to BuShips for special refit priority had been granted and Warlock's Warshawski sail tuners will have to be replaced, keeping the ship in dry dock for another eight weeks.
The following day, Honor is screened by Matsuko, who informs her that they have found evidence that Medusan shamans are raising an army of mekoha-addicted religious warriors to drive the Manticorans off their planet. Realizing that there is a deliberate attempt to engineer a major native uprising and escalate it into a deadly conflict, Honor suspects Haven is behind it. They decide to send an armed ten-man skimmer to the suspected staging area.
At a briefing with her senior officers, Honor informs them that they might be facing a covert operation by a foreign power. As the NPA is barred from getting involved with native religious matters, the Manticorans must first demonstrate direct off-world interference.
Ensign Tremaine points out that he has been monitoring the space-to-surface traffic, and that there does not seem to be any Havenite traffic anymore. At the same time, the freighter Sirius has been sitting in a parking orbit for over three months, allegedly due to technical problems with its Warshawski tuners. Lieutenant Commander Santos points out that this seems unlikely from an engineering point of view, and even if it were true, it would be much more convenient to get new tuners in Manticore than to wait for new parts coming in all the way from Haven.
Ensign Tremaine suggests a customs check of the ship, but Honor points out that it has already been cleared by Captain Young and that they need good reason to re-inspect it. Instead, she wants Tremaine to go by the ship in a cutter under a pretext and make a passive scan.
Once observing the freighter from a closer distance, Lieutenant Commander Santos discovers military-grade impeller nodes that are warmed up permanently. Realizing that the Sirius actually has military-grade propulsion, Honor contacts Commissioner Matsuko and tells her about her findings. She also prepares a dispatch for the First Space Lord, and has her Marines prepare for battle. Commander Suchon is sent to the surface while her more competent assistant, Fritz Montoya, is recalled to the ship.
NPA Lieutenant Frances Malcolm and her skimmer crew are ambushed and shot down by armed Medusan nomads. Malcolm manages to take out hundreds of the attackers with the skimmer's gun turret, but is eventually dragged out and murdered by them.
Honor is alerted to the situation by Maxwell Stromboli, who also tells her that the Sirius is breaking orbit. Honor instantly puts the Fearless on battle stations and has the impeller drive warmed up. Estelle Matsuko transmits an intercepted Havenite transmission informing the Sirius that the shaman leading the Medusan nomads had launched an assault and can no longer be controlled.
Honor sends her Marines to the surface and orders Lieutenant Venizelos to commandeer the first available ship and relay her declaration of Case Zulu to the Admiralty, signifying an imminent invasion of the Star Kingdom of Manticore. She then has the Fearless brush past the Havenite courier boat, destroying its aft impeller ring and trapping it in orbit. The Havenite commander protests, but she ignores him.
Honor explains to McKeon that she knows what is really going on: the Sirius, officially part of the Havenite trade mission on Medusa, is fleeing from the "violent uprising", and will "by chance" encounter a People's Navy squadron that will help put down the uprising and thereafter proclaim Haven's possession of the entire system on the grounds of Manticore's inability to maintain order. Honor decides that Sirius must be stopped, and is willing to take full responsibility for the consequences.
Papadapolous learns that Dr. Suchon refuses to approach the frontline, and orders his men to get her, by force if necessary. A massive attack by the Medusans follows, during which the Manticorans' superior weapons and air support mow down hundreds and thousands of enemies. Papadapolous then spots an aircar in a nearby cave, and orders one of his men to collapse the cave on the vehicle, and then moves in with his other troops. They find a dozen Havenites led by Colonel Westerfeldt, who fires at them and is shot and killed by Sergeant O'Brian.
As Fearless hunts Sirius to the hyper limit, Captain Harrington and the Havenite commander, Captain Johan Coglin, both contemplate their options. When the Manticoran cruiser comes up on its prey, Honor demands that the Havenite ship heave to for examination. Coglin does not respond, and she warns him that she will open fire on his ship if he does not comply.
Sirius drops her disguise, baring her hidden weapon systems, making the Manticorans realize that she is a Q-ship, a warship disguised as a civilian vessel. Honor, however, decides to engage nonetheless.
The two starships get closer, and eventually the Sirius opens fire; the First Battle of Basilisk ensues. Fearless, low on missiles due to the grav lance refit, must wait to get closer in order to have a chance to score a hit. Rafael Cardones is able to take out all missiles of the first volley, and Captain Coglin fires again, this time launching pairs of missiles every fifteen seconds. Fearless is able to evade this volley as well, but one warhead at least gets close enough to detonate.
Finally in firing range, Fearless returns fire, hitting one of the enemy ship's cargo holds. Sirius launches another large volley, and the Manticoran cruiser is hit in the forward impeller ring, and suffers heavy casualties in the Number One fusion plant room when it is opened to space.
Honor realizes that she has 43 minutes left to destroy the Sirius.
As the Fearless crew struggles to keep their ship running, it scores another hit on the Havenite ship.
One of Sirius' missiles detonates less than a thousand kilometers from Fearless' prow, doing terrible damage to the ship. Dominica Santos watches a young crew member be impaled by a piece of debris, while Lieutenant Webster has to report the loss of the communications section, with half his people in it. Santos still manages to give more energy to the propulsion systems, but then another two warheads hit. One kills nineteen crew members amidships, while a bomb-pumped laser beam from the other hits the bridge, killing Lieutenant Panowski and Chief Braun. Another beam destabilizes the Number One fusion bottle, forcing Santos to go there.
Honor sends her crew to new positions and continues the attack, hitting Sirius' starboard section, while Dr. Montoya tries to save Lieutenant Webster, whose rips have pierced his lung. The gunnery crew transfers a laser head missile to the working missile tube and Lieutenant Cardones fires it at the Sirius.
Dominica Santos manages to jettison Fusion One, but she, Allen Manning, and Angela Earnhardt are killed when the containment field collapses, along with forty other crewmembers. When Chief Killian is incapacitated, Honor herself has to take the helm.
Captain Goglin sees the Manticoran ship drift off course, and decides that he cannot let anyone but his own crew survive to tell of what happened. He orders his own ship to turn around. In response to that, Honor orders Lieutenant Cardones to hold position and bring up the grav lance. Sirius fires again, but Honor turns her ship, protecting it with its sidewall. Two beams still get through, destroying Fearless' last missile tube. At that point, Rafe Cardones fires the grav lance, taking down the enemy ship's electronics and sidewalls. Fearless then fires her last four energy torpedos, completely destroying the Sirius.
Honor Harrington looks out a window of Her Majesty's Space Station Hephaestus, watching the broken hull of HMS Fearless. She remembers how she and the surviving third of her crew struggled to keep the ship from falling apart, and how the entire Home Fleet was there to welcome the Havenite "routine visit" six days later.
The battered Fearless is to be scrapped, but her name is put on the List of Honor, keeping it in commission and its battle honors intact. Commander McKeon has been given command of the destroyer HMS Troubadour, while Honor will soon become commander of the brand new Star Knight-class heavy cruiser HMS Fearless (CA-286), with Andreas Venizelos as her executive officer. The Hauptman Cartel has been fined and the freighter Mondragon officially declared a prize, making Honor an instant millionaire.
Basilisk Station has been turned into a properly manned and defended naval station, while Captain Young and the Warlock have been banished to escort duty in the Silesian Confederacy. Though Haven's involvement in the whole affair could not be officially proven, everyone is sure of it. The People's Republic even went so far as to try Honor in absentia and sentence her to death for the "murder" of Sirius' crew. Manticore, on the other hand, has awarded her the Manticore Cross, one of the highest honors a citizen can receive.
At that point, Commodore Andrew Yerensky of the Weapons Development Board contacts Honor to invite her to discuss the "success" of the grav lance technology before an official panel. She assures him that she would be "delighted" to share her feelings about the grav lance with Admiral Sonja Hemphill and her colleagues.
A Note on Time