Beasts of Olympus 8: Unicorn Emergency by Lucy Coats
Eighth book in the Greek mythology BEASTS OF OLYMPUS series. Artemis, goddess of the hunt, has a unicorn emergency . . . Artemis, goddess of the hunt, has a unicorn emergency - something is sickening her wonderful wild herd, and if Demon, Official Beastkeeper to Olympus, can't save them, they'll become extinct. There's just one teeny tiny snag: unicorns HATE boys. So Demon finds himself disguised as a girl, and desperately trying to discover what's happening to make them so sick. If he can't find a cure, Artemis will feed him to her hounds! With a little help from his friends on Olympus, and the magic medicine box, Demon sets off to harness the power of moonlight and the stars to find a solution...