Arakawa and the Agent stand stunned as the hole in the island holding the Diclonius Research Institute grows wider and deeper, increasing the odds that the island will sink. The Agent takes Diana and is followed by an angry Arakawa as they seek to exit the doomed island while avoiding the hundreds of vengeful Clone Diclonii hunting them.
The agent recalls her orders from Saseba to infiltrate the facility and recover all research files possible, particularly on an Anti-Diclonius Birth Vaccine, before an attack being launched by the Japanese Self-Defense Force.
Arguing in circles with Arakawa, who the Agent does not realize has developed and is, in fact, carrying the vaccine, she ventures further into what remains of the facility, carrying the specialized crossbow once used by the Unknown Man and Bando. Arakawa is impressed by the weapon (given her hatred of Unknown Man, it seems likely she never saw him with this weapon), but the Agent is concerned for her lack of ammunition and the ability of some Diclonii to overcome the pain from its spiked iron balls.
Clearing a path with that and some high-caliber bullets, the Agent forges ahead, only to have to rescue Arakawa from a piece of floor that collapsed into a ledge. She demands that Arakawa drops the solid case she is carrying, which she finally does, which is when the Agent learns that the vaccine that was the reason for her mission was in the now-lost case.