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.

Out of the blue, a young Space Fleet officer's dream becomes reality: He's made captain of a starship. Just in time for the return of humanity's most terrible enemy, after 50 years of peace. To survive against this enemy, Captain Tad Thatcher will have to do more than learn how to become an effective commander, or how to wrangle his wayward crew. He will need to reinvent space combat. From scratch.

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.

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....

A derelict warship, ancient but still alive. A small team of humans fighting for all humanity. Built for a time when the races were just finding their way to the stars, finding that they could dominate others. The galactic conquests created the arms race and the ancients, the Progenitors had to protect their own. They built a ship to drive the others away.

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.

Nate has a talent for space combat after hundreds of victories in the Star Crusader videogame simulation. His skills are unique, enough to gain him a rare privilege: the chance to join five other Alliance cadets and escape the dull routine of the classroom. They will enter a fierce competition light-years away in the ancient Byotai Empire. Yet days after their arrival a rebellious faction begins a bloody mutiny that spreads like wildfire. The time for competition has ended; the time of war has begun.

A cease-fire that has lasted seven years... Worlds half-destroyed that have been rebuilt anew... Friends and crewmates scattered light-years apart... New leaders that would be kings... The Jung threat has been renewed, in ways not imagined. It will take a new savior to inspire the masses, and once again lead those willing to fight against oppression. But who will the new savior be?

The TDF Marco Polo embarks on its maiden voyage outside Earth's solar system, leading to the discovery of an extinct civilization destroyed by orbital bombardment. Deep underground is a mysterious library of alien secrets.

Former Marine Arthur Holland’s destiny begins when an aircraft crashes on his property in the mountains of Colorado. He moves to investigate and to help any survivors, but the closer he gets the less control he has of his movements. An unknown force urges him to open the door of the mysterious craft, discovering the secret that lies within: a dead, alien pilot and a peculiar, otherworldly crystal. If that wasn’t enough, the crystal feels like it is alive. That’s when he hears a single word inside his mind: run.

The year is 2126. It has been 30 years since Iran nuked Washington, DC. America has traded security for liberty following the attack, with the suspension of the Constitution and the Bill of Rights. The Constitution isn't even taught in schools anymore. In this environment, Dan "D2" Daniels, a retired army NCO of the old breed, sworn to protect the Constitution, finds a crashed spaceship and learns that Earth will soon be invaded. Using the technology from the spaceship, Dan forms an army of fellow senior veterans with two missions....

Mark Victor was a soldier left broken after the Harmony War ended. What can a broken ex-trooper really do? What are they good for if they've gone through the EMF and been tossed out the other side? If you were to ask Mark...Maybe, doing what the enemy couldn't and following his brothers and sisters. Mark wakes up to a nightmare, to an unfamiliar place with unknown faces. A planet under attack, an enemy he's never seen before. He just wants to escape, but when he sees others in danger, he realizes that a trooper stands for something; they stand to protect their own. No matter the cost.