The Hybrid a FanFic by Tehface
"Look for the signs, the keepers of the flame. They will lead you to war, and perhaps, to victory."
Posted by: GHOST REVOLVER
Halo Reach takes place during the events of The Fall of Reach (halo.wikia.com for more info). Pretty much, the planet Reach was a UNSC stronghold and no one thought it could fall, but it did after thousands of Covenant poured on the surface to find an artifact. Once they realized they had lost the artifact, they glassed the entire planet. During these events, the Spartan-IIs fought in a bunch of ground battles and John-117 and his team of two other Spartans took to space.
What you said. :)