As Sarah Palmer fights to get the Arbiter and the Brute Ambassador to safety, Captain Lasky sneaks behind enemy lines to reestablish communications with the UNSC Infinity. Their plans for escape are jeopardized, however, by a turncoat in their midst!
The survivors enter the depot to escape the Guardians of the Righteous' banshee fire. Inside, they are told by the Arbiter that due to Ealen IV's proximity to human space it was designed with a large maze of underground fortifications, which they could use to avoid further attacks. Spartan Ray, with her communications background, is put in charge of breaking the radio jam so the Arbiter's and Lydus' fleets know they are alive; she heads off with Captain Thomas Lasky. On the surface, Shipmaster Vata 'Gajat learns of the bunker and suggests besieging them to force the Jiralhanae to eventually hunt and kill the others for food. 'Gajat is ordered by a black clad human to assassinate the delegates quickly while their fleets are unaware of the attack.
On the Infinity the bridge crew begin investigating the loss of contact with the delegation. Their comms officer Lieutenant Jespersen confirms to Commander Bradley that both the Sangheili and Jiralhanae fleets are having the same problems. With so much plasma in Ealan IV's atmosphere, Lieutenant Ryder is unable to give an assessment of what caused the blackout, either. Gomez suggests deploying an ODST unit, but this is disregarded as diplomatic suicide. Lieutenant Jespersen picks up transmissions from the Jiralhanae ships demanding for an explanation for the loss of contact and accusing the Infinity of being responsible.
Back on the surface, the Guardians of the Righteous discover service tunnels leading to the bunker. The rebels do not react well to working faster, and 'Gajat assaults a Kig-Yar for providing useless information. 'Gajat points out that they have a mole in the delegation, so only need to wait for the signal to begin their attack. Underground, the Arbiter comes to the conclusion there is a spy amongst them due to the intense secrecy of the location of the conference. Lydus and the Arbiter are unwilling to allow the Spartans to save them and insist on joining in the fight against the Guardians of the Righteous. Lydus and his pack are paired with Spartan Scruggs and Fireteam Jackknife, while the Arbiter and his lance are paired with Sarah Palmer and Fireteam Bailey. As they leave the compound they are confronted by a Lich, proving to the Spartans as well someone is feeding the Guardians new information. Palmer has the Fireteams hand her their grenades. She fills her helmet with them and throws it at the Lich, causing a large explosion which downs the craft. However, a helmetless Palmer is confronted by a lance of Guardians on the ground.
In the plasma refinery, Captain Lasky and Spartan Ray search for communications equipment they can use to their advantage. Lasky plans to use the groundside equipment to triangulate the jammer's location so they can disable it. A Sangheili Guardian ambushes the two, though is taken down thanks to the teamwork of the two humans. Ray gets to the equipment and finds that the communications network itself is being used by the jammer, the Guardians having rigged it to broadcast on the entire bandwidth used for ship communications. She assures Captain Lasky she can use the equipment to find where the jammer is in the facility, however.
Outside, the Lich has crashed onto a catwalk. As it gives way, the delegation is forced to run for a gravity lift to avoid its collapse. Palmer is attacked by a Sangheili Guardian as they go up the lift and is saved by Spartan Scruggs. With everyone safe, Admiral Hood examines the dead Sangheili for communications equipment to explain how the Guardians knew where to find them. He finds a UNSC data pad hidden in his suit, containing profiles on the Spartans; Lasky and Hood. Hood becomes suspicious the Guardians are being used as mercenaries by a human traitor. Palmer sends Scruggs and his fireteam up ahead to secure a facility.
Back at the facility, Captain Lasky and Spartan Ray commandeer a pair of Banshees. Flying over the Guardians' base, they notice they are preparing to depart. Informing Palmer, the two groups come to the conclusion the Guardians will attack the delegation in full force. Palmer asks Scruggs if he was successful in taking control of the facility; he is the sole survivor, surrounded by the bodies of Sangheili and Spartans alike. He does not tell her this - only that the facility is secure.