Having proven himself capable of caring for the mythical creatures that dwell on Olympus, eleven-year-old Demon is summoned by the great god Hades to the Underworld to tend to Cerberus, the three-headed dog Guardian of the Underworld, which has been beaten by Demon's nemesis, Heracles.

Demon, the official Olympian beast keeper, must heal Ares's smelly dragon in time for battle, and will have to do it without his magic medicine box.

Demon's life on Mount Olympus taking care of injured beasts gets crazier when the goddess Psyche asks him to "borrow" Zeus's prized eagle for an urgent mission--an act which surely will incur the wrath of the king of the gods.

How will Demon, official Beast Keeper of Mount Olympus, heal a herd of sick unicorns before it's too late?
Demon has just returned from a trip to Asgard when a brand-new set of disasters fall into his lap. Not only does he have a groggy volcano monster to deal with, but something seems to be wrong with the unicorns, too. Demon's only clue is a mysterious note saying "Unicorn Emergency!" left on his bed. What does it mean? And how will Demon...