Two years have passed since the final battle with Sephiroth. Though Midgar, city of mako, city of prosperity, has been reduced to ruins, its people slowly but steadily walk the road to reconstruction. However, a mysterious illness called Geostigma torments them. With no cure in sight, it brings death to the afflicted, one after another, robbing the people of their fledgling hope.

自冷战结束后，大量职业军人退伍。但世界范围内恐怖活动与民族纷争不断，因此旨在向世界各地提供佣兵服务的“民间军事公司”应运而生。位于中东的沙漠地区，一辆卡车载着全副武装的恐怖分子和被他们拘押的人质来到沙漠腹地一个秘密据点。据点内外警戒严密，难以靠近。而在不远处的小山丘上，佣兵部队“猫屎一号”的波塔斯基（日野聪 配音）和帕奇（土田大 配音）正在执行监视任务。眼看人质遭到枪杀破坏，帕奇无法等待大部队，他在波塔斯基的掩护下只身闯入重兵把守的敌军阵营。近距离的搏杀，血脉贲张，生死攸关…… 本片根据漫画家漫画家小林源文的动物战争作品《Cat Shit One》改编。