Melanie Gate, a foundling with a peculiar talent for opening the unopenable, agrees to accompany a gearling automaton named Traveler on his quest to find a home, only to be pursued by the most dangerous wizard in the land and, along the way, discover her true powers.

Neither Cleo nor Evan like the new school librarian, Ms. Crowley, but they are very curious about where she disappears to at the back of the library, so one day they follow her--and find a secret door, a magical library full of locked books, and a letterfrom the previous librarian telling them that she is trapped somewhere between the covers of one of the enchanted books, and they must travel through the stories in order to save her.

In their third trip through the enchanted library, Cleo and Evan land in "The Werewolf's Curse" where Evan is promptly bitten by a werewolf, and the two need to find the cure--and the next key--before the full moon rises and Evan becomes stuck in this horror story forever.

When Evan and Cleo sneak into the enchanted library at night they find that Locke has already forced his way into a book, and when they follow they find themselves in a plane that promptly crashes into the Amazon rainforest--and with the help of a boy named Gabriel, (and a friendly sloth) they have to survive the jungle and find the golden statue that is the next treasure in their quest before Locke gets his hands on it.

Diego is under the spell of the wizard Maldred who wants to control the Naga, an enormous dragon that lives deep within the Earth, and plans to use Diego to steal the two keys necessary for that purpose; the first key is guarded by Argent, the silver dragon, and Jean his dragon master, so Drake, Bo, Carlos, and their dragons travel to Gallia to try and stop the theft and break the spell on Diego.