HALO: Envoy

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.    

Saskia, Dorian, Evie, and Victor aren't exactly friends at their small high school on the middle-of-nowhere colony world of Meridian. Each has their own problems, from absent parents to supporting their family, getting into a good college to making the next hit holo-film. But those problems were nothing next to the threat now facing their world: The alien alliance known as the Covenant is laying siege to Meridian. With their village in flames, the four teens find themselves stuck aboveground, locked out of the town shelter where the rest of the survivors are gathered. 

It's been three months since the colony world of Meridian was invaded by the alien alliance known as the Covenant. Under the close watch of the military, Evie, Dorian, Saskia, and Victor have been put into an accelerated training program with ONI, the Office of Naval Intelligence. And to the teens' surprise, ONI has a mission for them: return to their hometown on Meridian and monitor the Covenant's efforts to retrieve an ancient Forerunner artifact of untold power. But what seems like a simple job quickly spirals out of their control. 

Humanity has colonized the planets - interstellar travel is still beyond our reach, but the solar system has become a dense network of colonies. But there are tensions - the mineral-rich outer planets resent their dependence on Earth and Mars and the political and military clout they wield over the Belt and beyond. Now, when Captain Jim Holden's ice miner stumbles across a derelict, abandoned ship, he uncovers a secret that threatens to throw the entire system into war.

As a child, Chris Hooper dreamed of monsters. But in deep space, he found only darkness and isolation. Then, on planet LV178, he and his fellow miners discovered a storm-scoured, sand-blasted hell - and trimonite, the hardest material known to man. When a shuttle crashes into the mining ship Marion, the miners learn that there was more than trimonite deep in the caverns. There was evil, hibernating and waiting for suitable prey.