By Isabella Biedenharn
Updated July 28, 2015 at 12:00 PM EDT

The Dead House, Dawn Kurtagich’s debut thriller, centers on one terrifying event and its aftermath: Twenty years ago, a fire at Elmbridge High killed five teens — and caused one, Carly Johnson, to disappear completely. When a diary, owned by a girl named Kaitlyn Johnson, is found, even more mysteries arise. She only came out at night, and she shares a puzzling connection to Carly. Given the new evidence, police re-open the case and find that it was much darker than anyone thought.

To dip into the book before it’s published on Sept. 15, EW brings you the trailer for The Dead House, and an extremely visual exclusive excerpt, which compiles narrative and found material from the case.