The Chiropterans are among us. They have the ability to look like we look. But make no mistake, these bloodthirsty shape-shifters are not human, and it's up to the secret organization Red Shield to wipe them out, one by one. Elsewhere, Saya Otonashi is an amnesiac high school student who can't remember anything before the past year. When a man named Hagi appears and hands her a blade, Saya is hurled into the ongoing battle between Red Shield and the Chiropterans, where she just might fulfill a great destiny. Hans Zimmer provides the musical score for this imaginative 25-episode anime series. Contained here in the fourth volume are episodes 16-20.