U.C. 0080. It is winter in the southern hemisphere.
As Daryl and his Acguy team begin a new mission, Captain Monica launches "Operation Thunderbolt." The Spartan advances into a part of the ocean effectively controlled by the South Seas Alliance, and dispatches landing craft to perform reconnaissance.
As they wait for a report, Io and Bianca bond over their shared tastes in a musical jam session. Then the landing craft are attacked by Goggs and Z'Gocks from the Zeon remnant forces. Bianca sorties in her Guncannon Aqua, but is helpless against the Gogg piloted by underwater combat specialist Kaufmann. And Io's Atlas Gundam is likewise hard-pressed by an attacking Grublo.