So, I started work a while ago on a cross over fan fiction of Half Life 2 and Halo: Reach. I got the idea while playing Half Life 2 after making the connection between Freeman's HEV Mk IV and the MJOLNIR-series of power armor from Halo. Basically, the concept is to take the main characters of a game of Halo: Reach co-op game I played with my friend, and insert them into the world of Half Life to fight the Combine. The story around this, I decided, would be that Noble-6 and his under-appreciated, in some ways superior fighting comrade, Noble-6b (my Spartan, of course, if you didn't guess that already), never died in the Battle of Reach. Instead, after covering the retreat of Captain Keyes and the cruiser, UNSC Pillar of Autumn, the Spartans retreat further into the Aszod shipbreaking yards and link up with some of the last defenders of the planet Reach. This group of marines and army soldiers has been holding out in the fragmented hull of the frigate, UNSC Commonwealth, and after the Spartans help them fend off an attack by the Covenant, they join forces to fight their way to another pocket of UNSC resistance centered around the frigate UNSC Allegiance, which had been in the shipyards undergoing repairs since earlier in the battle. The Spartans lead the marines and troopers in a last defense of the Allegiance while her skeleton crew and other defenders complete final, frantic repairs of the ship. Boarding the vessel, they make a tense escape from the conquered planet, and barely escape through the orbiting Covenant fleets. However, during its escape, the Allegiance was engaged by a Covenant corvette, and suffered minor damage to its Shaw-Fujikawa slipspace drive. However, the ship proceeded with its FTL jump to escape the Covenant, but encountered an issue in its jump. At this point, the plot arc of my crossover intersects with that of Half Life 2. When the Allegiance bends a wormhole into space-time fabric, it interacts with the malfunctioning teleporter which Gordon Freeman is standing in in Dr. Kleiner's lab in the beginning of Half Life 2. That teleporter utilized Xen as a bridge between locations, and as the teleporter opened its rift to Xen, the Allegiance suffered a similar rift into Xen, and into the world of Half Life 2. So, the moment in time when Gordon Freeman appears outside of Dr. Kleiner's window is the same point in time at which UNSC Allegiance exits its slipspace jump over the ocean off the coast of the region around City 17, crash landing somewhere in the countryside.
