Killer Unicorns Series by Diana Peterfreund

Forget everything you ever knew about unicorns... Real unicorns are venomous, man-eating monsters with huge fangs and razor-sharp horns. Fortunately, they've been extinct for a hundred and fifty years. Or not. Astrid had always scoffed at her eccentric mother's stories about killer unicorns... moreForget everything you ever knew about unicorns... Real unicorns are venomous, man-eating monsters with huge fangs and razor-sharp horns. Fortunately, they've been extinct for a hundred and fifty years. Or not. Astrid had always scoffed at her eccentric mother's stories about killer unicorns. But when one of the monsters attacks her boyfriend—thereby ruining any chance of him taking her to the prom—Astrid finds herself headed to Rome to train as a unicorn hunter at the ancient cloisters the hunters have used for centuries. However, at the cloisters all is not what it seems. Outside, the unicorns wait to attack. And within, Astrid faces other, unexpected threats: from the crumbling, bone-covered walls that vibrate with a terrible power to the hidden agendas of her fellow hunters to—perhaps most dangerously of all—her growing attraction to a handsome art student ... an attraction that could jeopardize everything. less

Astrid Llewelyn is now a fully trained unicorn hunter, but she can't solve all her problems with just a bow and arrow. Her boyfriend, Giovanni, has decided to leave Rome, the Cloisters is in dire financial straits, her best friend's powers seem to be mysteriously disintegrating, and Astrid can't help but feel that school, home, and her hopes of becoming a scientist are nothing but impossible dreams... moreAstrid Llewelyn is now a fully trained unicorn hunter, but she can't solve all her problems with just a bow and arrow. Her boyfriend, Giovanni, has decided to leave Rome, the Cloisters is in dire financial straits, her best friend's powers seem to be mysteriously disintegrating, and Astrid can't help but feel that school, home, and her hopes of becoming a scientist are nothing but impossible dreams. So when she's given the opportunity to leave the Cloisters and put her skills to use as part of a scientific quest to discover the Remedy, Astrid leaps at the chance. Finally, she can have exactly what she want--or can she? At Gordian headquarters, deep in the French countryside, Astrid begins to question everything she thought she believed: her love for Giovanni, her loyalty to the Cloisters, and most of all her duty as a hunter. Should Astrid be saving the world from killer unicorns, or saving the unicorns from the world? less