In the middle ages, an old monk used his powers and a bone quill to ink a magical manuscript, the Book of Beasts. Over the centuries the book and the quill were lost. And so were the secrets contained in the book. But now someone is tracking down the lost Book of Beasts, page by page, and reassembling it.

Twins Matt and Em Calder are Animare-just like their ancestor, the monk. The things they draw can be brought to life, sometimes with disastrous consequences. Now Matt and Em are being watched-hunted-because only they can use the Book of Beasts and the bone quill to release the terrible demons and monsters their ancestor illustrated.

Matt and Em have no choice: They must get to the bone quill fast. But time is not on their side. Someone else is closing in on the quill, and the revelation of whom that is will destroy Matt and Em's world...