With the Covenant War over, the Office of Naval Intelligence faces old grievances rising again to threaten Earth. The angry, bitter colonies, still with scores to settle from the insurrection put on hold for thirty years, now want justice—and so does a man whose life was torn apart by ONI when his daughter was abducted for the SPARTAN-II program. Black ops squad Kilo-Five find their loyalties tested beyond breaking point when the father of their Spartan comrade, still searching for the truth about her disappearance,prepares to glass Earth’s cities to get an answer. How far will Kilo-Five go to stop him? And will he be able to live with the truth when he finds it? The painful answer lies with a man long dead, and a conscience that still survives in the most unlikely, undiscovered place.

The second novel of the Kilo-Five Trilogy by #1 New York Times bestselling author Karen Traviss—part of the expanded universe based on the award-winning video game series Halo! 2553. Welcome to humanity’s new war: silent, high stakes, and unseen. This is a life-or-death mission for the Office of Naval Intelligence’s black-ops team, Kilo-Five, which is tasked with preventing the ruthless Sangheili, once the military leaders of the alien alliance known as the Covenant, from regrouping and threatening humankind again. What began as a routine dirty-tricks operation—keeping the Sangheili occupied with their own insurrection—turns into a desperate bid to extract one member of Kilo-Five from the seething heart of a brutal civil war. But troubles never come singly for Kilo-Five. Colonial terrorism is once again surfacing on one of the human worlds that survived the war against the Covenant, and the man behind it is much more than just a name to Spartan Naomi-010. Meanwhile, the treasure trove of Forerunner technology recovered from the Forerunner shield world of Onyx is being put to work, even as a kidnapped Sangheili plots vengeance on the humans he fears will bring his people to the brink of destruction…

WELCOME TO HUMANITY’S NEW WAR: SILENT, HIGH STAKES, AND UNSEEN. This is a life-or-death mission for ONI's black-ops team, Kilo-Five, which is tasked with preventing the rutheless Elites, once the military leaders of the Covenant, from regrouping and threatening humankind again. What began as a routine dirty-tricks operation - keeping the Elites busy with their own insurrection - turns into a desperate bid to extract one member of Kilo-Five from the seething heart of an alien civil war. But troubles never come singly for Kilo-Five. Colonial terrorism is once again surfacing on one of the worlds that survived the war against the Covenant, and the man behind it is much more than just a name to Spartan-010. Meanwhile, the treasure trove of Forerunner technology recovered from the shield world of Onyx is being put to work. And a kidnapped Elite plots vengeance on the humans he fears will bring his people to the brink of destruction.

The Covenant has collapsed after a long, brutal war that saw billions slaughtered on Earth and her colonies. For the first time in decades, however, peace finally seems possible. But though the fighting's stopped, the war is far from over: it's just gone underground. The UNSC's feared and secretive Office of Naval Intelligence recruits Kilo-Five, a team of ODSTs, a Spartan, and a diabolical AI to accelerate the Sangheili insurrection. Meanwhile, the Arbiter, the defector turned leader of a broken Covenant, struggles to stave off civil war among his divided people. Across the galaxy, a woman thought to have died on Reach is actually very much alive. Chief scientist Dr. Catherine Halsey broke every law in the book to create the Spartans, and now she's broken some more to save them. Marooned with Chief Mendez and a Spartan team in a Forerunner slipspace bubble hidden in the destroyed planet Onyx, she finds that the shield world has been guarding an ancient secret – a treasure trove of Forerunner technology that will change everything for the UNSC and mankind. As Kilo-Five joins the hunt for Halsey, humanity’s violent past begins to catch up with all of them as disgruntled colony Venezia has been biding its time to strike at Earth, and its most dangerous terrorist has an old, painful link with both Halsey and Kilo-Five that will test everyone’s loyalty to the limit.

An all-new digital single—part of the New York Times bestselling series based on the blockbuster Xbox® games! The military-grade artificial intelligence known as Iona has only one week to live. After that, the UNSC will legally terminate her seven-year existence in order to stave off the threat of the data corruption phenomenon known as “rampancy,” a condition that will eventually take hold of her functionality and persona, endangering all those around her. In a last-ditch effort to save herself, Iona has successfully launched an unprecedented legal appeal against her own death sentence—a case being watched very closely at not only the highest levels of human government, but by others with a very different agenda…

The bestselling adaptation of the iconic video game Halo: Combat Evolved featuring the Master Chief—part of the expanded universe based on the award-winning video game series! 2552. Having barely escaped the final battle for Reach against the vast alien alliance known as the Covenant, the crew of the Pillar of Autumn, including Spartan John-117—the Master Chief—and his AI companion Cortana, is forced to make a desperate escape into slipspace. But their destination brings them to an ancient mystery and an even greater struggle. In this far-flung corner of the universe floats a magnificently massive, artificial ringworld. The crew’s only hope of survival is to crash-land on its surface and take the battle opposing the Covenant to the ground. But they soon discover that this enigmatic ringworld is much more than it seems. Built one hundred thousand years ago by a long-lost civilization known as the Forerunners, this “Halo” is worshipped by the Covenant—a sacred artifact they hope will complete their religious quest for supposed transcendence, and they will stop at nothing to control it. Engaging in fierce combat, Master Chief and Cortana will go deep into the Halo construct and uncover its dark secret and true purpose—even as a monstrous and far more vicious enemy than the Covenant emerges to threaten all sentient life on Halo and the galaxy beyond…

This collection dives into the Halo universe from the perspective of those who fought and died to save humanity—and those who vowed to wipe it out.