Claire Martinson still worries about her older sister Sophie, who battled a mysterious illness last year. But things are back to normal as they move into Windermere Manor . . . until the sisters climb a strange ladder in a fireplace and enter the magical land of Arden. There, they find a world in turmoil. The four guilds of magic no longer trust each other, the beloved unicorns have disappeared, and terrible wraiths roam freely. Scared, the girls...

Claire Martinson and her sister Sophie have decided to stay in Arden--the magical land they discovered by climbing up a chimney in their great-aunt's manor. If what they've learned is true, the sisters are the last descendants of the royal family, and only a true heir of Arden--with magic in her blood--can awaken the unicorns. Since Sophie has does not have magic, the land's last hope rests on Claire. The sisters journey to Stonehaven, a famed Gemmer...