An invisible Willwear is causing massive damage in random attacks across Tokyo. Unit 8 tracks the Willwear down to the quagmire zone, a hotbed of illegal immigrant activity. The area is a lawless zone, so Sena is sent to infiltrate as a civilian garbage collector. There, he meets an illegal immigrant from a equatorial nation, who he suspects of being involved in the attacks. When he strikes up a friendship with the man, however, he's forced to choose between his personal feelings of respect, and his duty.
