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.    

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.

The year is 2033. The world has been reduced to rubble. Humanity is nearly extinct and the half-destroyed cities have become uninhabitable through radiation. Beyond their boundaries, they say, lie endless burned-out deserts and the remains of splintered forests. Survivors still remember the past greatness of humankind, but the last remains of civilisation have already become a distant memory. Man has handed over stewardship of the earth to new life-forms.

After discovering a cache of Prothean technology on Mars in 2148, humanity is spreading to the stars---the newest interstellar species, struggling to carve out its place in the greater galactic community. On the edge of colonized space, ship commander and Alliance war hero David Anderson investigates the remains of a top secret military research station---smoking ruins littered with bodies and unanswered questions. Who attacked this post, and for what purpose?

When the Imperial prison barge Purge—temporary home to five hundred of the galaxy’s most ruthless killers, Rebels, scoundrels, and thieves—breaks down in a distant part of space, its only hope appears to lie with a Star Destroyer found drifting and seemingly abandoned. But when a boarding party from the Purge is sent to scavenge for parts, only half of them come back—bringing with them a horrific disease so lethal that within hours, nearly all aboard the Purge die in ways too hideous to imagine.