Later, after Alex is almost killed by the intruders in her room, she and Paul determine that the letters are responsible for what is happening to them. However, when they attempt to locate the letters to destroy them, the packet has disappeared. Now, they must find and destroy another "trigger" in order to close the deadly doorway.

Their quest to find this trigger takes them first to Northern Arkansas (where they encounter another, particularly viscious entity), and then to the haunted battlefield of Shiloh, where they come face-to-face with the full horror of Stehle's Door. Ultimately, it is Paul, the weaker of the siblings, who must face the full power of the fatal doorway and its deadly emissaries.

William M. O’Brien Jr. lives in San Antonio, Texas, with his wife, daughter, three dogs, and three cats. His wide range of interests and activities are generally reflected in the writing he does. An avid reader of both fiction and non-fiction, he chooses fiction as the area in which to write, combining horror, history, and the occult in his first novel, Stehle’s Door. The material for the novel comes from a variety of sources. "As a life-long teacher, I’ve always had a fascination for young people," Mr. O’Brien says. "I’ve often wondered what certain youngsters would do in a life-or-death situation." Much of the suspense of Stehle’s Door is built around this supposition. "Immaturity in the face of adversity always provides an interesting situation," he adds. Another area reflected in the novel is Mr. O’Brien’s infatuation with antiques and artifacts. "Each one has a story to tell," he says. "I find myself wishing they could talk." A Civil War artifact plays a key role in Stehle’s Door.