U.C. 0079, March. The Principality of Zeon begins its Earth invasion operation, overrunning the planet's surface with its huge, humanoid mobile suits. The Earth Federation Forces mount a hopeless resistance using conventional tanks and missile launchers, but they are no match for Zeon's mobile suits. Then, after months of hard fighting, a turning point comes in the form of the European counteroffensive codenamed Operation Odessa...