Jessica Day George

Orphaned Anthea Cross hopes to finally find a home with her long-lost uncle, but she soon learns not only that he secretly breeds forbidden horses, but that she can communicate with them.

Eleven-year-old Princess Celie lives with her parents, the king and queen, and her brothers and sister at Castle Glower, which adds rooms or stairways or secret passageways most every Tuesday, and when the king and queen are ambushed while travelling, it is up to Celie--the castle's favorite--with her secret knowledge of its never-ending twists and turns, to protect their home and save their kingdom.

When the dangerous ancient wizard Arkwright escapes the dungeon and goes missing within the Castle, Princess Celie must find the wizard and save her family.

Creel's adventures continue when she, her brother, and her betrothed travel across the seas to visit their dragon friends and become involved in a battle against an alien group of dragons that has kidnapped Queen Velika, endangering her and her expected litter of hatchlings.

"Castle Glower's towers have transported Princess Celie, her siblings, and her pet griffin, Rufus, to an unknown land. As they set out on a dangerous adventure to discover their whereabouts, they find an entire lost people, divided by the wishes of two wizards in a centuries-old quarrel over their beloved home--Castle Glower"--

Anthea gathers her friends to meet with the antagonistic emperor of Kronenhof, hoping to find Coronami princess Margaret, the herd stallion, and other horses her mother has taken before war breaks out.