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.

2559. It has been a year since the rogue artificial intelligence Cortana seized control of the Domain, an otherworldly dimension housing a vast information network. With an array of Forerunner weapons at her disposal, Cortana set out to enforce an authoritarian peace on the civilizations of the galaxy. But as the United Nations Space Command flagship Infinity prepares to strike against Cortana at Zeta Halo, another plan has also been set in motion.

As kids, the three of them were inseparable; as soldiers, they would be torn apart. Marcus Fenix and Dominic Santiago fought alongside Dom’s elder brother Carlos at Aspho Fields in the epic battle that changed the course of the Pendulum Wars. There’s a new war to fight now, a war for mankind’s very survival. But while the last human stronghold on Sera braces itself for another onslaught from the Locust Horde, ghosts come back to haunt Marcus and Dom.

For centuries, mankind has searched for nonhuman civilizations in the cosmos. These lost alien societies have finally been discovered—but they were destroyed long ago. Devin Starn starts off as a lowly rock rat aboard Borag, a mining ship working the dangerous end of the asteroid belt. Slowly, he gains prestige and purpose. When an alien base is uncovered, however, he must risk everything to protect his ship and her crew. What wiped out all the civilizations that came before humanity?

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....