The 26th century. Humanity has expanded beyond Earth’s system to hundreds of planets that colonists now call home. But the United Earth Government and the United Nations Space Command is struggling to control this vast empire. After exhausting all strategies to keep seething colonial insurrections from exploding into a full-blown interplanetary civil war, the UNSC has one last hope.

In the 25th century, humans have conquered space. The advent of faster-than-light travel has opened up hundreds of habitable planets for colonization, and humans have exploited the virtually limitless space and resources for hundreds of years with impunity. So complacent have they become with the overabundance that armed conflict is a thing of the past, and their machines of war are obsolete and decrepit. What would happen if they were suddenly threatened by a terrifying new enemy?

Earth is no longer the center of the universe. After the invention of the faster-than-light jump drive, humanity is rapidly establishing new colonies. But the vast distances of space mean that the old order of protection and interstellar law offered by Earth has ceased to exist. When a nearby world attacks, the new colony of Glenlyon turns to Robert Geary, a young former junior fleet officer, and Mele Darcy, a onetime enlisted marine.

The Hundred Worlds have withstood invasion by the relentless Hok for decades. The human worlds are strong, but the Hok have the resources of a thousand planets behind them, and their fleets attack in endless waves. The long war has transformed the Hundred Worlds into heavily fortified star systems. Their economies are geared for military output, and they raise specialized soldiers to save our species. Assault Captain Derek Straker is one such man among many.

A world recovering from a devastating plague. A brutal enemy threatening invasion. A young man seeking to escape the shadow of his father. A ship manned by a crew of fresh academy graduates. A top-secret experimental propulsion system. A questionable alliance with a mysterious green-eyed woman. What destiny has in store for the crew of the UES Aurora is far greater than any of them could ever imagine. And this is only the beginning....

The Confederation has fought three wars against the forces of the totalitarian Union. Three generations of its warriors have gone off to war, held the line against the larger, more powerful enemy. Now the fourth conflict is imminent, and the Confederation's navy is on alert, positioned behind the frontier, waiting for the attack it knows is coming.

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.

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 almost a century of peaceful exploration and colonization of space, the United Earth Space Force stumbles across a shockingly xenophobic alien race that has more and better armed ships and refuses all attempts at contact. As the outgunned Space Force is driven back in battle after battle in what appears to be a war of extermination, one officer experiences precognitive visions that help him blunt the enemy onslaught, but he can't control or predict when they occur.

Captain Mitchell "Ares" Williams is a space marine and the hero of the Battle for Liberty whose shot heard 'round the universe saved the planet from a nearly unstoppable war machine. He's handsome, charismatic, and the perfect poster boy to help the military drive enlistment. Pulled from the war and thrown into the spotlight, he's as efficient at charming the media and bedding beautiful celebrities as he was at shooting down enemy starfighters.

Returning home after a training exercise, Captain Jonathan Somerville and his ship, HMS Achilles, stumble into the middle of the warzone. Stranded behind enemy lines, the crew of Achilles must fight their way through occupied territory if they are to link up with coalition forces and help turn back the invaders.

Harmon Tomeral wanted nothing more than to go to space. Sent to an orphanage when his parents were killed in a sandstorm, the odds were stacked against him. Despite that, he made it to the academy and graduated in the top 10 percent of his class...only to find out the fleet did what it wanted, regardless of regulations, and he came from the wrong planet. He didn’t give up his dream, though, because where there’s a will, there’s a loophole, and Harmon and his friends found their loophole in the Top Fleet Marine competition - the winner would get 100,000 credits....

A forgotten colony of humans live on a water world circling a tiny, faded star on the edge of the galaxy. The crew of their newest flagship, the Rampart, encounters an alien scout who is being chased by a dangerous foe. The encounter shakes the beliefs held by the people of Lashmere. With the aid of the mysteries of the origin tablet, they discover the true origins of their colony. These may be the last humans in the universe. Can they survive against their ancient enemy? Their only choice is to embrace an unknown past and fight with everything they have.

The plot by the Galactic Union’s Mercenary Guild against the Four Horsemen has culminated in an invasion of Earth. Faced with an overwhelming force, the human mercs had no choice. They’ve fled, leaving Sansar Enkh to go to the Mercenary Guild headquarters on Capital Planet to stand trial for humanity. On the run, Jim Cartwright and Nigel Shirazi have travelled to the Winged Hussars’ secret base of New Warsaw, in an effort to convince Alexis Cromwell to join the fight, while the other mercenaries who escaped the fall of Earth have gone to the perceived safe haven of Karma.

The Confederated Systems Alliance has spread to dozens of systems, creating the first true interstellar alliance dedicated to bringing peace and prosperity to all inhabited worlds. Unfortunately, some see this new alliance as a threat to their own seats of power, and would do anything to stop it. After a well deserved rest, Captain Nathan Scott is once again called into action. This time, it is not the fate of the galaxy that is on his shoulders, but the life of one of his dearest friends. But not all is as it appears.