Many millennia ago, the human race was enslaved by the An - a fearsome alien people whose cruel empire once spanned the galaxies, until they were defeated and consigned to oblivion. But a research mission to the planet Ishtar has made a terrifying - and fatal - discovery: The Ahanu, ancestors of the former masters, live on, far from the reach of Earth - born weapons and technology ... and tens of thousands of captive human souls still bow to their iron will.

The Year is 2040. The Marines have landed on Mars to guard the unearthed secrets of an ancient and dangerous alien race: Ourselves. Scientists have discovered something astonishing in the subterranean ruins of a sprawling Martian city: startling evidence of an alternative history that threatens to split humanity into opposing factions and plunge the Earth into chaos and war.

Dev Cameron joined the military to fly a starship but is rated unsuitable and grudgingly accepts an assignment with the ground forces, piloting a massive walking tank (a warstrider). But Cameron may yet get a chance at glory when he makes a discovery about the alien foes that could change the course of the war.

Chaos has erupted throughout the known galaxy, threatening countless colonies and orbital habitats - as the Associative struggles vainly to keep the peace. Extreme measures are called for in these times of dire crisis, and the Star Marines are awakened from their voluntary 850-year cybe-hibe sleep. But General Trevor Garroway and his warriors are about to discover that the old rules of engagement have drastically changed.

The year is 2162. Thirty-eight years after first contact, Lord Commander Grayson St. Clair leads the Tellus Ad Astra on an unprecedented expedition to the Galactic Core, carrying more than a million scientists, diplomats, soldiers, and AIs. Despite his reservations about their alien hosts, St. Clair is deeply committed to his people - especially after they're sucked into a black hole and spat out four billion years in the future. Civilizations have risen and fallen. The Andromeda Galaxy is drifting into the Milky Way. And Earth is most certainly a distant memory.

In the 20th century Earth sent probes, transmissions, and welcoming messages to the stars. Unfortunately, someone noticed. The Galactics arrived with their battle fleet in 2052. Rather than being exterminated under a barrage of hell-burners, Earth joined their vast Empire. Swearing allegiance to our distant alien overlords wasn't the only requirement for survival. We also had to have something of value to trade, something that neighboring planets would pay their hard-earned credits to buy. As most of the local worlds were too civilized to have a proper army, the only valuable service Earth could provide came in the form of soldiers....

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.

Five days after Owen Zastava Pitt pushed his insufferable boss out of a 14th story window, he woke up in the hospital with a scarred face, an unbelievable memory, and a job offer. It turns out that monsters are real. All the things from myth, legend, and B-movies are out there, waiting in the shadows. Some of them are evil, and some are just hungry. Monster Hunter International is the premier eradication company in the business. And now Owen is their newest recruit.

Idealistic Navy Lieutenant Jacob Grimm just wanted to honor his mother’s sacrifice in the last great war. When he’s forced to return fire and destroy a squadron of ships to save his own, he thinks he’s the hero...until they discover the ships are full of children. Disgraced and denied promotion, Jacob’s career is over. That is until the head of ONI needs a disposable officer to command a battered destroyer on the rim.

The year is 2108, and the North American Commonwealth is bursting at the seams. For welfare rats like Andrew Grayson, there are only two ways out of the crime-ridden and filthy welfare tenements: You can hope to win the lottery and draw a ticket on a colony ship settling off-world...or you can join the service. With the colony lottery a pipe dream, Andrew chooses to enlist in the armed forces for a shot at real food, a retirement bonus, and maybe a ticket off Earth.

Growing up, Travis Uriah Long yearned for order and discipline in his life...he two things his neglectful mother couldn’t or wouldn’t provide. So when Travis enlisted in the Royal Manticoran Navy, he thought he’d finally found the structure he’d always wanted so desperately. But life in the RMN isn’t exactly what he expected. Boot camp is rough and frustrating; his first ship assignment lax and disorderly; and with the Star Kingdom of Manticore still recovering from a devastating plague, the Navy is possibly on the edge of budgetary extinction.

From the bottom of the oceans of the world a hidden threat stalks mankind—probing, testing our weapons and defenses, biding time to strike. In the summer of 2039, this aquatic foe unleashes surprise attacks against coastal cities around the globe. Mankind faces a sophisticated new enemy, arrived from the depths of space and lurking in the dark blackness of the seas.

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.

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.

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.