Years after defeating aliens bent on burning down the galaxy, the Interstellar Union is breaking apart, its member species undermining each other at every opportunity. When an interdimensional distress signal arrives, only humanity is interested in helping. Captain Vin Husher is given command of the UHS Relentless, and sent in as part of a carrier strike group...right into a trap laid by humanity’s old enemy. Surrounded by a bioengineered super-species and unable to return home, Husher must draw on decades of experience just to keep his people alive.

More than two centuries after World War III poisoned the planet, the final bastion of humanity lives on massive airships circling the globe in search of a habitable area to call home. Aging and outdated, most of the ships plummeted back to Earth long ago. The only thing keeping the two surviving lifeboats in the sky are Hell Divers - men and women who risk their lives by skydiving to the surface to scavenge for parts the ships desperately need.

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.

Engines. Genetically modified warriors that keep the great Nova Alliance war machine churning against the enemy Coalition. Most days, Engines are all that stand between salvation and chaos. Led by legendary Engine Captain Akira Hayashi, Shadow Squad has fought on the frontlines for a decade. They are on the brink of victory when the Coalition launches a series of desperate and devastating attacks that cripple the Nova Alliance restoration sites vital to save the dying planet.

Captain Keyes is loved by the public but hated by Command. He captains the UHS Providence, an aging supercarrier and the last human ship not dependent on dark tech - technology humanity has used to rule over the galaxy since barely defeating the Ixa in the First Galactic War. Dominance has come at a cost. Over the decades, old allies have grown resentful, and when dark tech itself fails, Captain Keyes’ predictions start coming true: those old allies are now enemies.

Opportunities there are few and far between…that is unless you're willing to put on a uniform. For ace-pilot Deborah Allen Riker (a.k.a “Admiral Dare”), life had never been easy. She's defended Earth against countless enemies, both alien and human alike. Now a civilian and academic living on the fringes of civilized space, she has committed herself to a life of solitude and studying a race of long-dead aliens. Everything was great…until she finds herself dragged into a new conflict. A conflict she never saw coming.

Commander David Bryce is scheduled to lead a routine re-supply run for the Orbital Development Group (ORB) to the fledgling colony on Mars. Without warning, he’s taken away by government agents and told the mission parameters have changed. They’ve discovered something. And it’s drifting closer to Earth. Atlas Donovan tirelessly hunts for an artifact, and tracks the piece to Lake Como, Italy. After the recent news from ORB, Atlas is more drawn to the trail than ever.

Commander Dalton Reeves is a maverick officer with exceptional genetic strength and a dark family history—a history that will come back to haunt him. Punished for exceeding orders one time too many, he’s packed off to the "The Abyss"—the most dangerous space station in the galaxy. But a posting that should have led to five years in obscurity will propel Reeves into the center of an interstellar war against a long-forgotten alien adversary with a bitter grudge.

Doug Lancer is on the run. When the peace-keeping military known as the Federation and the law-enforcing Galactic Rangers join forces, forming the Galactic Empire, things quickly go south, especially for anyone not on-board. Hunted by his former brothers, Lancer is reduced to bounty-hunting to survive. When his path crosses with an ex-imperial fighter pilot fleeing the Empire, things get even worse.

Two civilizations clash. A rebellion grows. The fate of the galaxy hangs in the balance. Technical Chief "Pappy" Gunther is a grizzled, burning-out commando in the United Earth Armed Forces. He ponders a return to civilian life, yet feels a strong sense of belonging to his elite team. When colonists on a far-flung world request aid, a task force from several allied systems is assembled. Pappy and his crack unit are sent to investigate and to engage a mysterious alien force from beyond.