Hidden Enemy - The Living Oracle, #2

Return to the world of The Last Oracle! With the destruction of the barrier protecting our world from the lost realm of Faerie, conflict rises between the Wardens and the magical adepts who created it. While most adepts understand Helena's role in eliminating the barrier, some adepts, angry with the loss of their life's work, call for her to restore it. And one adept may want her dead. A series of mysterious poems leads Helena and Malcolm on a hunt for someone whose powers of illusion defeat even the Wardens' skills.
As the enigmatic figure stalks Helena, only her oracular gift stands between her and a madman who believes she's someone she isn't. But what can even an oracle do against an enemy who strikes from the shadows?