The Unicorn Chronicles consists of four books by author Bruce Coville.
The first book, Into the Land of the Unicorns, Cara Hunter, and her grandmother, Ivy Morris. Ivy sends Cara into the world of Luster, by way of an amulet, where she must find the Old One, Queen Arabella Skydancer, and give her a message sent by Ivy.
The second book, is about Cara's journey back to Earth to fetch her grandmother back to Luster. Upon arriving back on Earth, she encounters Beloved, who is determined to have Cara's amulet that transports her between the two worlds.
The conclusion to the series, The Last Hunt, concluded the 4-book series of the Unicorn Chronicles.