It's possible you're thinking of one of the following:
* "The House" by Frank Peretti: This is a standalone novel by Frank Peretti, not co-written with Ted Dekker. It's a supernatural thriller about a family who moves into a seemingly ordinary house with a dark history.
* "The Books of the Ancient" by Ted Dekker: This is a series by Ted Dekker, not co-written with Frank Peretti. It involves a young man who receives a mysterious book that unlocks hidden powers and secrets about the world.
Could you please clarify the book title and authors you are referring to? This will help me provide you with accurate information about the role you are asking about.