(U.C. 0079.04.29 - 0079.05.11) As the Earth Drop Operations begin, the 603rd is assigned to test the Hildolfr, a transformable mobile tank. The piloting task falls onto Maj. Demeziere Sonnen, a formerly respected tank trainer who is now disgraced and troubled by dope addiction from his own misery after Zeon abandoned armored vehicles in favor of mobile suits. When the team drop into Arizona for field testing, they find the drop zone supply depot destroyed — by a team of Zakus captured by LtC. Federico Czariano's Federation squad. Sonnen is forced into combat with the uncalibrated Hildolfr. The fast and powerful mobile tank proves its mettle by taking out all enemies, but not without the cost of Sonnen's life.