Across the six-planet expanse of the Gaia System, the Earthlike Gretia struggles to stabilize in the wake of an interplanetary war. Amid an uneasy alliance to maintain economies, resources, and populations, Aden Robertson reemerges. After devoting fifteen years of his life to the reviled losing side, with the blood of half a million casualties on his hands, Aden is looking for a way to move on. He’s not the only one. A naval officer has borne witness to inconceivable attacks on a salvaged fleet. A sergeant with the occupation forces is treading increasingly hostile ground.

There he was in his sailboat in the middle of the Atlantic, all alone and loving it. Well, there was a US Navy carrier group on his southern horizon, but he was a Navy guy himself, so he didn't mind. Then came the UFOs, hurtling in from the Outer Black to overfly the carriers at Mach 17. Their impossible aerobatics were bad enough—but then they started shooting at each other, and at the Navy, with nukes. Little ones at first, but winding up with a 500 megatonner at 90 miles that fried every piece of electronics within line-of-sight.

Two centuries after humanity colonized the stars, new dangers emerge. The peaceful inhabitants of the Conclave are threatened by expanding alien powers. Invaders threaten the star cluster, attacking our fringe settlements. Captain Bill Gorman has mysteriously disappeared. His clone, set aside for a dark day like this, awakens and begins to put together the pieces. What’s gone wrong out on the frontier? Why are our colonies being attacked by aliens while the Conclave worlds dream of better days? And what happened to the original Captain Gorman?

Mars and the Moon have been colonized, piracy runs rampant in the asteroid belts, and a thriving society grows in the depths of space. Humanity prepares to embark upon its greatest journey - the colonization of Alpha Centauri. Then, everything changes. A deep space reconnaissance probe discovers a new Earth-like planet 12 light-years from Earth’s sun. The probe also finds something unusual, something unnerving. A new mission is created, a space fleet is formed, and humanity embarks on unravelling the greatest mystery of all - the origins of life itself.

After two brutal, bloody struggles for their very existence against implacable alien foes, humanity is victorious, but not at peace. As distrust and accusations consume the political discourse between the two major factions, the Eastern Star Alliance military has already begun executing small raiding missions into United Terran Federation space. The Federation fleet, still reeling from the last war, is in no shape to try and protect its own borders.

Geary believed in the Alliance. Even when he uncovered overwhelming evidence that the highest echelons of the government and fleet command were involved in secret programs and prison camps, he believed it was worth saving. He believed his duty was to see that justice was served even though some factions feared that revealing the truth would cause the Alliance to crumble. But after narrowly surviving two assassination attempts when he brings evidence of the misdeeds to the capital star system, Geary realizes that some want to get rid of him.

In the early 22nd century, humanity has spread through the solar system - and their electromagnetic signals have traveled hundreds of light years. An alien race called the Oghaldzon has decided that mankind is dangerously insane...and must be forcibly taken under control. The invasion fleet's technology is decades ahead of Earth's best. They have more ships than the human fleets combined, and a seemingly-inexhaustible number of ground troops. And they're not afraid to kill billions of people.

"Triplanetary" is a science fiction novel and space opera by author E. E. Smith, published in 1948. It consists of two parts. The first explains the series background, which consists of a conflict between the evil Eddorians and the benevolent Arisians. This conflict is carried out throughout the history of an oblivious humankind on Earth. The final part of the book, which was originally published as a magazine story, takes up the tale after civilization has been rebuilt.

For 17 years, Colonel Henry Wong and the United Planets Space Force have fought the Kenmiri Empire. They drove the alien overlords back from humanity's borders into their own stars and found allies among the Kenmiri's slaves and subjects. Now the war is over. A great Gathering has been called of the allies who fought the war, but they only ever shared a common enemy. With the Kenmiri in retreat, a thousand new agendas are revealed.

Lieutenant Sam Bitka, US Naval Reserve, is getting used to civilian life when he is called back to active duty. Tensions between Earth and the alien Varoki are on the rise, and Sam is assigned as tactical officer aboard the deep space destroyer USS Puebla. Dispatched to the distant world of K'tok to protect human colonists, he wants nothing more than to serve out his active duty time and get back to his civilian life. But when the Varoki launch a crippling surprise attack against the Earth coalition fleet, Sam finds himself suddenly in command of the USS Puebla.

Despite economic and territorial tensions, no one wants the city-states of the Eight Worlds to repeat the Terran Collapse by going to war. But when war accidentally happens, everyone seeks ways to exploit it for gain. The Landry and Peregoy ruling dynasties see opportunities to grab territory, increase profits, and settle old scores. Exploited underclasses use war to fuel rebellion. Ambitious heirs can finally topple their elders’ regimes - or try to.

A year ago, the war against the Theocracy ended. But it didn't bring peace. Admiral Kat Falcone was lucky - her side won the war. But without an external threat, Kat’s homeworld government, the Commonwealth, begins to burst. The galactic war may be over, but there is a civil war on the horizon. The king and parliament disagree over the Commonwealth's future. The Commonwealth's first recession is plaguing corporations.

Humanity has reached an uneasy truce with the Empire—but unless the allies bring the fight to the enemy, extinction is all but assured. In preparation for the inevitable next war, Commander Stephen Michaels is at the helm of the Archangel Squadron, and his orders are simple: go rogue. Disguised as mercenaries, Commander Michaels and the Archangels seek valuable intelligence on their imposing foe. Their mission takes them deep into uncharted territory, where they make inroads with the Empire, fiercely guarding their true identities and purpose.

Captain Isaac Gallant is the only son of the dictator of the Confederacy, his career slowed by a dozen measures to protect his reputation and safety alike - but he has no intention of being a pampered child. He is determined to do his duty. An attempt to force his crew to acknowledge their own duties puts his ship in a unique position to intervene when an overwhelming rebel attack is launched on one of the Confederacy’s most critical facilities.

Earth is conquered. Sol is lost. One ship is tasked to free them. One Captain to save them all. When an alien armada destroys the United Earth Space Force and takes control of the human homeworld, newly reinstated Captain Annette Bond must take her experimental hyperspace cruiser Tornado into exile as Terra's only interstellar privateer. She has inferior technology, crude maps, and no concept of her enemy, but the seedy underbelly of galactic society welcomes her so long as she has prizes to sell and money to spend.