Books like 'Catalyst Gate'
Readers who enjoyed Catalyst Gate by Megan E. O'Keefe also liked the following books featuring the same tropes, story themes, relationship dynamics and character types.
sc-fi space action / adventure military, war & conflict space-opera aliens lgbtq ai suspense military
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Into the Serpent's Lair by Ryk Brown
Rated: 4.76 of 5 stars · 17 ratingsEmpires at the brink of war…A galactic alliance on the horizon…Worlds on the verge of destruction…Comrades taking up arms against one another…Nathan Scott must use all his cunning to save not only his own world, but the worlds of his friends and his enemies. But to do so, he must make a deal with the devil, and risk everything on a fight no one believes he can win... -
![Retaliation by Ryk Brown]()
Retaliation by Ryk Brown
Rated: 4.50 of 5 stars · 12 ratingsPart 2: Episode 10 A ship unable to defend itself… A captain determined to revive her… Worlds dependent on them both to survive… An enemy bent on their destruction… With the Aurora unable to fight, the Karuzari Alliance must find a way to not only repair their flagship, but to make the enemy pay dearly. Sometimes, you just have to make do with what you've got... -
![Retribution by Jason Anspach, Nick Cole]()
Retribution by Jason Anspach, Nick Cole
Rated: 4.60 of 5 stars · 20 ratingsVICTORY is at hand. With the galaxy in tatters, Chhun and Wraith lead Kill Team Victory and the remnants of the Legion in a clandestine final effort to bring about Article Nineteen... -
![Mountain of Mars by Glynn Stewart]()
Mountain of Mars by Glynn Stewart
Rated: 4.52 of 5 stars · 24 ratingsThe Mage-King of Mars is deadChaos rocks Olympus MonsA new monarch must rise – but she does not stand alone!As the celebration of the victory at Legatus cools, a shuttle accident claims the lives of the Mage-King of Mars and his heir. The Crown and the Mountain fall to the Mage-King’s daughter, seventeen-year-old Kiera Alexander...Categorized as:
aliens espionage exploration military political-intrigue space-opera space-travel suspense -
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![A Price Too High by Ryk Brown]()
A Price Too High by Ryk Brown
Rated: 4.59 of 5 stars · 20 ratingsPart 2: Episode 12 …An enemy in retreat …A new world to protect …A new potential ally on the horizon …A new chance to go on the offensive The Dusahn have taken a massive blow, and with the Aurora’s improved jump range, Captain Scott and the Karuzari Alliance can finally keep them at arms length... -
![Mage-Commander by Glynn Stewart]()
Mage-Commander by Glynn Stewart
Rated: 4.55 of 5 stars · 20 ratingsSome soldiers are the shields of innocent soulsOthers are the fanatics of their causeAnd for them…no war is ever truly over!Tempered on the anvil of the war against the secessionist UnArcana Worlds and tested against the evil of Project Orpheus, Mage-Commander Roslyn Chambers has risen through the ranks of the Royal Martian Navy to serve as second-in-command of one of their most prestigious...Categorized as:
aliens exploration military space-opera space-travel suspense action-adventure adult -
![Blockade: Age of Expansion - A Kurtherian Gambit Series by Craig Martelle, Michael Anderle]()
Blockade: Age of Expansion - A Kurtherian Gambit Series by Craig Martelle, Michael Anderle
Rated: 4.50 of 5 stars · 10 ratingsHumanity’s greatest export – Justice. Space is a dangerous place, even for the wary, especially for the unprepared. The aliens have no idea. Here comes the Bad Company. When the Bad Company learns of a human colony blockaded by aliens, they take the upgraded War Axe into battle. Once again, nothing is as it seems, but this time, they find a single enemy, evil to its core...Categorized as:
aliens exploration military space-opera space-travel action-adventure adult audiobook -
![Elvians by S.H. Jucha]()
Elvians by S.H. Jucha
Rated: 4.50 of 5 stars · 10 ratingsTwo crises challenge the Omnians. Alex Racine’s fleet draws a first-contact conflict, which faces the Ollassa, a symbiotic flora race. The Omnian fleet sails from alliance space in an effort to interdict an alien ship that arrives at the Worlds of Lights, the Ollassa system. Soon after arriving, the alien ship deploys machines to scour asteroids for resources in the system’s far belt... -
![SADEs by S.H. Jucha]()
SADEs by S.H. Jucha
Rated: 4.50 of 5 stars · 10 ratingsDangerous forces are at work across galactic space that the Omnians are attempting to stabilize, but their resources are severely strained. The SADEs, self-aware digital entities, express to Alex Racine and Renée de Guirnon their desire to know the method of their creation. Alex and Renée, the Omnian co-leaders, want to obtain the knowledge for the SADEs, who are humans’ closest allies... -
![Secrets in the Stars by Mackey Chandler]()
Secrets in the Stars by Mackey Chandler
Rated: 4.50 of 5 stars · 10 ratingsWhen Lee Anderson and her parents discovered a new world teeming with life, it was the dream of every explorer: they were rich beyond their imaginations. But tragedy struck when a herd of creatures overran their camp and killed her parents. The only other adult in her life had been their partner Gordon, who adopted her as parent. Which didn’t turn out to be easy, because he wasn’t human... -
![A Grimm Decision by Jeffery H. Haskell]()
A Grimm Decision by Jeffery H. Haskell
Rated: 4.50 of 5 stars · 10 ratingsFrom USA Today bestselling author Jeffery H. Haskell comes book six in the military science fiction epic in the tradition of Honor Harrington and Star Trek...Categorized as:
space-opera military suspense space-travel exploration political-intrigue sci-fi fiction -
![Delphi Colony by Bob Blanton, Jessica Gurd]()
Delphi Colony by Bob Blanton, Jessica Gurd
Rated: 4.42 of 5 stars · 12 ratingsBook 8 of the popular series Delphi in Space. The McCormacks are finally going to start an Earth Colony and the Paraxeans are finally getting a home. Catie is going to the Academy and Marc is going to Artemis... -
![Delphi Challenge by Bob Blanton, Jessica Gurd]()
Delphi Challenge by Bob Blanton, Jessica Gurd
Rated: 4.42 of 5 stars · 12 ratingsBook 9 of the popular series Delphi In Space Delphi. In it, we find the McCormacks having to defend Artemis from the same Aliens that attacked the Paraxean colony fleet over 70 years before. Follow along as Catie finally graduates from the Academy... -
![Nua'll by S.H. Jucha]()
Nua'll by S.H. Jucha
Rated: 4.42 of 5 stars · 12 ratingsThe Omnian expeditionary fleet sails for the faraway place they call “the wall.” The worlds of humankind have consolidated their resources to create a powerful armada to confront the alien federation.During the Omnians’ previous encounter with an alien fleet at the wall, the Nua’ll comm sphere spoke to them in multiple languages...Categorized as:
aliens exploration military space-opera space-travel action-adventure adult audiobook -
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![Delphi Diversion by Bob Blanton]()
Delphi Diversion by Bob Blanton
Rated: 4.42 of 5 stars · 12 ratingsCatie is on her way back to Earth after having settled the Fazulan slaves when the wormhole her ship is traveling in collapses. They are diverted to another system where big chunks are flying around. They rescue a ship and find themselves in the middle of a series of mysteries...Categorized as:
aliens exploration military space-opera space-travel action-adventure audiobook book -
![Rising Force by Ken Lozito]()
Rising Force by Ken Lozito
Rated: 4.42 of 5 stars · 12 ratingsEight months have passed since the Star Shroud barrier was engaged to protect the Earth, but it won’t last, and humanity is scrambling to build a fleet. Cut off from home, the crew of the Athena has taken refuge on the Boxan colony world, a last safe haven for the creators of the Star Shroud... -
![Star Scrapper by J.N. Chaney, Matt Goodwin]()
Star Scrapper by J.N. Chaney, Matt Goodwin
Rated: 4.42 of 5 stars · 12 ratingsThe war against the AI was won but a new threat is rising. Hank Spears is content with his life as a scrapper until he unearths an artificial intelligence who warns him of a grave threat to all life in the universe. Since AI has long been outlawed and anyone caught harboring one is imprisoned or executed, the two must go on the run, fleeing into the far reaches of space... -
![Chimera's Star by Glynn Stewart]()
Chimera's Star by Glynn Stewart
Rated: 4.42 of 5 stars · 12 ratingsHistory holds many secrets.The frontier holds many shadows.One ship may damn all mankind.One ship may save them.In a bold and brazen act of treachery, the Royal Martian Navy exploratory cruiser Rose was stolen and is now in the hands of the conspiracy group known as Nemesis... -
![Distant Horizon by J.N. Chaney, Terry Maggert]()
Distant Horizon by J.N. Chaney, Terry Maggert
Rated: 4.56 of 5 stars · 18 ratingsThe Universe is a bloody mess. Time to put on your cleaning gloves.During a routine arrest, Van discovers a stolen spacecraft, its importance far greater than it first appears. Fast, sleek, and beautiful, the ship is a cultural relic from Linulla’s people, and returning their property will set off a chain of events that reveals a new adversary... -
![Return of the Corinari by Ryk Brown]()
Return of the Corinari by Ryk Brown
Rated: 4.61 of 5 stars · 16 ratingsPart 2: Episode 13 A host of new allies… A plethora of advanced technologies… A daring gamble to advance their forces… A chance to retake lost worlds once and for all… The Dusahn have been backed into a corner, barely able to hold the worlds of the Pentaurus cluster, let alone the entire sector. Forced to dig in, they may have to resort to drastic measures to save their fledgling empire... -
![Balance by Ryk Brown]()
Balance by Ryk Brown
Rated: 4.43 of 5 stars · 24 ratingsPart 2: Episode 5 An entire sector in turmoil... Neighbors who appear unconcerned... A favor asked of an old friend... Sacrifices made for the good of humanity... Before they can challenge the Dusahn and prevent them from expanding their empire further, the Karuzari must first gather much needed resources. But doing so could be more difficult than anticipated...Categorized as:
aliens exploration military space-opera space-travel action-adventure adult audiobook -
![Lunar Crisis: Age of Expansion by Tom Dublin, Michael Anderle]()
Lunar Crisis: Age of Expansion by Tom Dublin, Michael Anderle
Rated: 4.67 of 5 stars · 6 ratingsThe Shadows have been blooded and survived. There was no time for celebration as their next mission came upon them like a gangster in the night. Or missiles out of the blue.Captain Jack Marber, the Yollin Tc’aarlat, and Adina Choudhury take the ICS Fortitude to the moons of Taglen...Categorized as:
aliens exploration space-opera space-travel military sci-fi action-adventure fiction -
![A Darker Magic by Glynn Stewart]()
A Darker Magic by Glynn Stewart
Rated: 4.42 of 5 stars · 24 ratingsA bloody war has ended in a restored peaceAnd the shield of Martian magic guards the starsTwo centuries of spell and steel to ward all humanityTwo years ago, Lieutenant Commander Roslyn Chambers stood witness to the surrender of the last remnants of the Republic...Categorized as:
aliens exploration military space-opera space-travel suspense action-adventure adult -
![Junkyard Spaceship by Jamie McFarlane]()
Junkyard Spaceship by Jamie McFarlane
Rated: 4.46 of 5 stars · 21 ratingsWhen aliens threaten his country, one grumpy old vet will take the fight to the stars.Albert Jenkins would like nothing more than to putter around his junkyard, selling parts and working on old cars. When an alien spacecraft is shot down by US Air Defense and crash lands on his newly rebuilt home, he’s dragged back into the fight of his life...Categorized as:
aliens exploration military space-opera space-travel action-adventure adult audiobook -
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![All in Good Time by Mackey Chandler]()
All in Good Time by Mackey Chandler
Rated: 4.50 of 5 stars · 8 ratingsLiving by bad neighbors is hard. Especially when there is a whole mob of them. Needing to do business with them makes it harder. Imagine nine billion noisy disrespectful neighbors who can’t keep their word and would be just as happy to see you dead... -
![Shield of Terra by Glynn Stewart]()
Shield of Terra by Glynn Stewart
Rated: 4.45 of 5 stars · 20 ratingsThe mother, ruler of an entire world Sent to the heart of an old enemy to build a new peace The daughter, officer of a deadly warship Sent to the darkness to find the new enemy hunting them all A dozen inhabited worlds of the Kanzi Theocracy and the A!Tol Imperium are ash...Categorized as:
aliens exploration military space-opera space-travel suspense action-adventure adult -
![Bane of Worlds by Anthony James]()
Bane of Worlds by Anthony James
Rated: 4.40 of 5 stars · 10 ratingsFollowing his successful mission to recover the missing warship ESS Crimson, Captain John Duggan finds himself unredeemed in the eyes of his superiors. His duties resume and this time he’s given something easy - escort a cargo ship to a distant planet and bring it home safely. But war is never so predictable and a straightforward mission becomes something much more important... -
![Crusade by Glynn Stewart]()
Crusade by Glynn Stewart
Rated: 4.40 of 5 stars · 10 ratingsA newborn Alliance, forged to stop the destroyers of worldsA potential ally, with secrets hidden by a thousand liesA long-doomed star, whose ruins hold a vital answer... -
![Galactar by Anthony James]()
Galactar by Anthony James
Rated: 4.40 of 5 stars · 10 ratingsFollowing decades of war and the recent catastrophic loss of an entire planet, the Human Planetary Alliance is riven by internal disputes and rivalries. The military’s old guard fights for power against those who see a chance to turn things around.After a series of hard-fought victories, Captain Carl Recker is becoming recognized as a man who gets results - a man who knows how to beat the Daklan... -
![Fulcrum Gun by Anthony James]()
Fulcrum Gun by Anthony James
Rated: 4.40 of 5 stars · 10 ratingsLost in hostile space and pursued by the most powerful warship in the known universe, Captain Carl Recker is losing hope and running out of options. His battleship Fulcrum is no match for this enemy and the Meklon aliens who might have helped him are dead, killed by the Galactar’s murderous weaponry.Somehow, Recker must find a way to succeed where the might of an alien empire already failed... -
![Laws of Ancidium by Anthony James]()
Laws of Ancidium by Anthony James
Rated: 4.40 of 5 stars · 10 ratingsHaving fought his hardest battle, Captain Carl Recker returns to planet Lustre, bringing the alien battleship Fulcrum with him.Recker is under no illusions that he’ll be offered backdated shore leave, but his feet don’t even touch the ground before trouble shows up. A heavily armed fifty-thousand-metre Meklon interstellar drops out of lightspeed near the planet... -
![Tasmanian SFG: Welcome to Hell by C.R. Daems]()
Tasmanian SFG: Welcome to Hell by C.R. Daems
Rated: 4.40 of 5 stars · 10 ratingsJolie was three when she found she was ugly and deformed. She was five when she found she was a sub-human and an outcast. She was seven when five boys and two girls dragged her out of the orphanage and beat her unconscious, leaving her lying bleeding and broken in the street. She was content to lie there and die, tired of being hated and abused...Categorized as:
aliens military political-intrigue space-opera suspense action-adventure assassins audiobook -
![Alliance by S.H. Jucha]()
Alliance by S.H. Jucha
Rated: 4.40 of 5 stars · 10 ratingsOlawale Wombo and a small contingent of Omnians are sent to assist Earth to uplift its technological prowess. With the aid of the incomparable SADEs, advanced tech is transferred to the Sol Enclave, the system’s governing body.After Sol’s construction of Tridents, Omnian-designed warships, Earthers possess the ability to transit quickly among the stars... -
![The Long Voyage of the Little Fleet by Mackey Chandler]()
The Long Voyage of the Little Fleet by Mackey Chandler
Rated: 4.40 of 5 stars · 10 ratingsIn the first book of this series "Family Law", Lee's parents and their business partner Gordon found a class A habitable planet. They thought their quest as explorers was over and they'd live a life of ease. But before they could return and register their claim Lee's parents died doing a survey of the surface... -
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![Shakedown by Scott Sigler]()
Shakedown by Scott Sigler
Rated: 4.40 of 5 stars · 10 ratings"A gritty tale of cosmic dread.”— Pierce Brown, #1 New York Times Bestselling author of RED RISINGFew know the warship’s actual name. Fewer still know what it really is. And almost no one knows of its unique ability, an ability that could tilt the balance of power if not outright win the war.But everyone has heard the rumors. Rumors about the worst place the Planetary Union Fleet can send you...Categorized as:
space-opera military aliens espionage exploration space-travel political-intrigue sci-fi -
![Refuge by Glynn Stewart]()
Refuge by Glynn Stewart
Rated: 4.36 of 5 stars · 11 ratingsA dying world, shattered by a broken machineA desperate flight, their only hope for refugeA robotic race, ally and destroyer alikeThe Republic of Exilium has grown in strength and confidence at the far end of the galaxy from the rest of mankind, sending out scout ships to survey the worlds around them as they try to learn more about the mysterious Construction Matrix AIs... -
![Artifact Space by Miles Cameron]()
Artifact Space by Miles Cameron
Rated: 4.42 of 5 stars · 21 ratingsOut in the darkness of space, something is targeting the Greatships.With their vast cargo holds and a crew that could fill a city, the Greatships are the lifeblood of human occupied space, transporting an unimaginable volume - and value - of goods from City, the greatest human orbital, all the way to Tradepoint at the other, to trade for xenoglas with an unknowable alien species...Categorized as:
aliens exploration military space-opera space-travel suspense action-adventure adult -
![Stowaway by Z.D. Dean]()
Stowaway by Z.D. Dean
Rated: 4.33 of 5 stars · 12 ratingsLt Zade, on his last days of his last deployment to Afghanistan, still couldn’t find the excitement he so desperately needed. A chance encounter, on his last mission, sends him hurtling through space on the Unity exploration ship XES01. Surrounded by aliens, Zade must quickly learn to interact with the non-soldiers on the crew... -
![Omnia by S.H. Jucha]()
Omnia by S.H. Jucha
Rated: 4.33 of 5 stars · 12 ratingsAlex Racine, who led an elite group of humans and SADEs (self-ware digital entities), left the newly discovered planet of Celus-5 under difficult circumstances. Few of the Harakens with Alex thought there was little he could do to bring peace to the embroiled planet...Categorized as:
aliens exploration military space-opera space-travel action-adventure adult audiobook -
![Duty Calls: The adventure continues by James Haddock]()
Duty Calls: The adventure continues by James Haddock
Rated: 4.33 of 5 stars · 12 ratingsDuty Calls continues the story of Nic, Mal, Jazz and Jade as they fight to hold what belongs to them. The Corporations are becoming more aggressive in their effort to steal their inventions. Our four friends are matching the corporate's aggression blow for blow. The fight has already turned deadly, and the Corporation has shown they aren't afraid to spill blood... -
![Allora by S.H. Jucha]()
Allora by S.H. Jucha
Rated: 4.33 of 5 stars · 12 ratingsUntil the Confederation created Allora, it had produced SADEs (self-aware digital entities) for hundreds of years with enormous consistency and harnessed their capabilities to power the society. But this particular, young SADE was disturbed by her confinement... -
![Celus-5 by S.H. Jucha]()
Celus-5 by S.H. Jucha
Rated: 4.33 of 5 stars · 12 ratingsFor the Sojourn’s initial mission, the Haraken explorer ship undertakes the investigation of Celus-5, a world identified by Willem, a SADE (self-aware digital entity), and his team of scientists, as the best prospect for a new colony.What should be a routine survey mission becomes a disaster. To the Harakens’ surprise, they discover, not one, but two alien species engaged in conflict...Categorized as:
aliens exploration military space-opera space-travel action-adventure adult audiobook -
![Exile by Glynn Stewart]()
Exile by Glynn Stewart
Rated: 4.31 of 5 stars · 13 ratingsA shackled Earth, ruled by an unstoppable tyrantAn exiled son, and a one-way trip across the galaxyA perfect world, their last hope for survivalVice Admiral Isaac Gallant is the heir apparent to the First Admiral, the dictator of the Confederacy of Humanity. Unwilling to let his mother's tyranny stand, he joins the rebellion and leads his ships into war against the might of his own nation...Categorized as:
aliens exploration military space-opera space-travel action-adventure adult audiobook -
![Space Team: Planet of the Japes by Barry J. Hutchison]()
Space Team: Planet of the Japes by Barry J. Hutchison
Rated: 4.31 of 5 stars · 13 ratingsWhile trying to stop a cyber-attacker stealing all Space Team's hard-earned money, the cyborg, Mech, unlocks a secret partition in his hard drive, revealing a mysterious set of co-ordinates. The co-ordinates lead the team to Funworld, a planet-sized theme park with a worrying number of artificially intelligent clownbots, and a shocking disregard for Health & Safety... -
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![Diplomatic Immunity by Lois McMaster Bujold]()
Diplomatic Immunity by Lois McMaster Bujold
Rated: 4.20 of 5 stars · 25 ratingsA rich Komarran merchant fleet has been impounded at Graf Station, in distant Quaddiespace, after a bloody incident on the station docks involving a security officer from the convoy's Barrayaran military escort. Lord Miles Vorkosigan of Barrayar and his wife, Lady Ekaterin, have other things on their minds, such as getting home in time to attend the long-awaited births of their first children...Categorized as:
aliens espionage military political-intrigue space-opera space-travel suspense action-adventure -
![Spinward Fringe Broadcast 6: Fragments by Randolph Lalonde]()
Spinward Fringe Broadcast 6: Fragments by Randolph Lalonde
Rated: 4.29 of 5 stars · 14 ratingsThe crew of the Triton continue their misadventure near Ossimi Ring Station. They are forced down different paths and a fight for freedom that will cost them dearly begins. New opportunities, dangers and experiences await them all, as the Order of Eden stirs, advancing their own agenda... -
![Haraken by S.H. Jucha]()
Haraken by S.H. Jucha
Rated: 4.29 of 5 stars · 14 ratingsNine years of tranquility came to an abrupt end when a Méridien starship entered the Hellébore system, sounding a dire warning for Alex Racine, the Haraken president. Unwanted visitors had arrived again. But this time, they’re not alien; they’re human... -
![Sol by S.H. Jucha]()
Sol by S.H. Jucha
Rated: 4.35 of 5 stars · 24 ratingsSol’s warships paid the ultimate price for threatening the Haraken and New Terran worlds. Now, Haraken President Alex Racine and his Méridien partner, Renée de Guirnon, are engaged in a desperate gamble to stop a war between their worlds and United Earth’s (UE) massive forces before it starts... -
![Mage-Provocateur by Glynn Stewart]()
Mage-Provocateur by Glynn Stewart
Rated: 4.38 of 5 stars · 21 ratingsVengeance hunts them. Rebellion seeks them. Loyalty commands them. The shadows will fear them. Captain David Rice and Mage Maria Soprano have made their choice, signing up with the Martian Interstellar Security Agency and converting Red Falcon into a covert operations ship for the Protectorate...Categorized as:
aliens espionage exploration military political-intrigue space-opera space-travel action-adventure -
![The Meridian Ascent by Richard Phillips]()
The Meridian Ascent by Richard Phillips
Rated: 4.34 of 5 stars · 24 ratingsIn their battle to save Earth from becoming another conquest of the alien Kasari Collective, Mark and Heather Smythe have struck crucial blows against the enemy. But their best efforts have still failed to derail the completion of the wormhole gateway that would give the insidious extraterrestrial invaders access to the planet—and doom humankind as helpless slaves of the Kasari hive mind...Categorized as:
aliens espionage exploration political-intrigue space-travel suspense action-adventure adult
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