Edgeworks Entertainment

Erda Renadee follows the Spartans to the crash site of the Human starship, killing the last few ODSTs left there. The Spartans arrive at Mt Jefferson and start to get set up, but before they know it, Erda's army appears outside the gates and begins the siege of Mt Jefferson.

Responding to the Spartans' call for help, a small flotilla of UNSC ships appears in orbit. They are quickly destroyed by the Covenant fleet, but not before many ODSTs make it to the surface alive. Meanwhile, the Spartans return to Delta Base and find it occupied by Erda Renadee's Elites, and are forced to find a new home. After hooking up with the ODSTs and their leader, Sergeant Henderson, who were holed up in the wreckage of their destroyed ship, the Humans make their way to a remote mountain fortress called Mt Jefferson.

The Praetor and the Cleric are fighting again, this time about whose fault it was that the prisoner escaped. The Foreman announces that he has found a potential entrance through a ventilation shaft, but the Cleric does not allow the blasting that would be required to open the tunnel. The Cleric then makes a chilling remark: if the Praetor does not act quickly, the Cleric will arrest him and take over the operations around the Codex.

After sneaking into the cave through an abandoned mineshaft, the Spartans get into position and launch the attack. They rescue Green 4 from his cell and fight their way out of the cave, but Green 2 sacrifices his life to buy them time so they can escape.

Green 2 goes on a walk alone out in the field near Delta Base, remembering the day his whole team was killed. When asked about what he is thinking by Jack, he admits that he is having regrets about leaving his team. In the meantime, Lykurgus intercepts a Covenant signal hinting at a Human prisoner being held in the Olympia caves, and the decision is made to rescue him.

The Praetor delivers a welcome address to the Foreman and his Engineers, who have come to excavate the rest of the Codex and attempt to activate it. After his speech, the Praetor notices several of the Cleric's Seraphim guarding a door. He dispatches the Special Operations Commander to investigate, but she is blocked when the Captain of the Seraphim arrives on the scene. When she returns with a lance of her Special Operations Elites, she finds the room empty and abandoned. However, unbeknownst to her, the Cleric had already ordered that the contents of that room be brought before him for interrogation. It is a prisoner: a Spartan known as Green 4.

As waves of Elites assault the base, the Spartans inside are forced to fall back and relinquish the dock. Jack, who had been guarding the dock, looks out into the Covenant army and sees a Red Officer commanding the nearby forces. He quickly decides to eliminate that commanding officer, and starts a death-defying rampage across the field to get to him. After killing him, though, Jack is cornered by Covenant artillery and infantry. But just before they can fire, Blue Team miraculously appears in the Warthogs and slices through the Covenant lines, throwing the Elites into disarray.

As Blue 2 alerts the other Spartans to the presence of the Elites, the trap is sprung. Hordes of Covenant rush the Humans, who quickly fall back into a corner. As Blue Team prepares to make its last stand, they radio Delta Base for reinforcements, only to learn that Delta Base is itself under attack by a massive Covenant army. After a long bombardment, the Spartans at Delta Base retaliate with a volley of rockets and prepare to defend the base.

The Praetor learns of Green 2's position, and thus the location of Delta Base, by tracking the captured Banshee. He orders an expedition be sent under Erda Renadee, the Battlefield Commander, to destroy the Spartan base. Meanwhile, Blue Team arrives at the dish at the top of the Codex, with a mission to encode a signal into the bursts sent out by the structure. Although they sense that something is wrong, they cannot find any Elites in the entire complex. The Elites are cloaked, setting up a checkmate move with which they can eliminate all of the Spartans at once, and thus minimize the casualties. Finally, though, Blues 1 and 2 manage to find two uncloaked Elites and reveal the potential ambush. An alarm is raised, and the Spartans prepare for battle.

Back at Delta Base, the Chief and Red Team prepare to join the fight against the Covenant. Green 2 makes his way back to the base in the captured Banshee, but not before almost being shot out of the sky by Blue Team. As everyone arrives at the base, Jack comes out to meet Candy, and they have a less than warm exchange. Before they can really lay into each other, though, they are called into the Briefing Room to talk to Lykurgus and the Chief. The four of them discuss their options, and decide to attempt encoding a message into the energy bursts sent out by the Codex in an effort to contact Earth. Blue Team is given the mission, while Red Team is ordered to hang back and help plan future strategy against the Covenant.