Ellis, a young girl suspected of murdering a prominent physicist Heinrich Schneider, is on the run from an underground society called "Hunters" when she is tracked down by the bounty hunter Nadie in a small Mexican town. However, instead of turning her in, Nadie impulsively decides to help her and the two girls embark on a journey to Ellis' hometown, where they plan on finding clues about her past. (myanimelist.net)