Missing body, creepy library

You and Tina sneak your way quietly to the back of the third floor. First you look were you left your brother. The body is gone. You hope he is ok. The wrought iron spiral staircase is no more than twenty feet away. You breath a sigh of relief it appears to be empty.

Tina looks back at you. "In here Jack."

You walk into a library. Clearly no money was spent updating this portion of the house. Still, the ceilings are high, and covered with ornate copper tiles. Several spots on the floor have less dust, from now missing furniture. The shelves are built into the walls. The wood is expensive, mahogany perhaps, but in disrepair and dusty. You frown the books have long ago been stolen.

In frustration you hit a paneled wall with your fist. The noise echoes. The panel is hallow.

"Tina, this is hollow. There is something back here."

The two of you feel the wall and soon find a hidden switch. You toggle it and the panel slides open. Inside there are about fifty books. They are all old, and probably all valuable.

You skim read the spines. The books are in alphabetical order by author. You quickly find Farasset. You pull out a copy of his first book 'The Fabric of Reality'. It is written in his own handwriting. You come across a chapter called The Mathmatics of Black Magic. You don't think that chapter was in the published version. Still nothing about the array.

You hand off the book to Tina and grab the next book on the shelf, 'Altering Space and Time'. You skim a bit. The book is darker. Farasset was clearly headed down path toward madness. The final chapter talks about changing reality itself using an array, but the are no details.

You feel defeated. You take one last look on the shelf. Curiously the next book has no title or author. You pull it out and open it. It is by Farasset. You flip to the end. This book is unfinished and you realize unpublished. It is titled 'Devil's Reality, the End'. You begin to read. You soon come to a diagram of the array.

"This is it Tina!"

Crash

"What was that?"

"Keep reading, Jack I'll check it out."

You barely make it through another sentence, when you hear Tina's scream. You look over. Tina is gone. You are so close to figuring out how to shut down the array.