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.

During a test flight for the world’s first warp engine, Major Noah Gantz is set to go down in the history books. Despite years of training, the mission goes sideways, and instead of a quick trip to the moon and back, Noah's ship is transported across the universe to stars unknown.

On the planet Tython, the ancient Je’daii order was founded. And at the feet of its wise Masters, Lanoree Brock learned the mysteries and methods of the Force - and found her calling as one of its most powerful disciples. But as strongly as the Force flowed within Lanoree and her parents, it remained absent in her brother, who grew to despise and shun the Je’daii, and whose training in its ancient ways ended in tragedy. Now, from her solitary life as a Ranger keeping order across the galaxy, Lanoree has been summoned by the Je’daii Council on a matter of utmost urgency.

The jungle planet of Haruun Kal, homeworld of the legendary Jedi Master Mace Windu, has become a battleground in the increasing hostilities between the Republic and the renegade Separatist movement. The Jedi Council has sent Depa Billaba - Mace’s former Padawan and fellow Council member - to Haruun Kal to train the local tribesmen as a guerrilla resistance force. But now the Separatists have pulled back, and Depa has not returned.