Shadow of Shaniko (Hardcover, Turtleback School & Library ed.)

The ghost town of Shaniko, Oregon isn't supposed to be dangerous, but the howling going on in the Shaniko School night after night tells Meggie and Paige otherwise. A ghost? They are terrified when threatening messages begin appearing on the chalk board in the school, warning them to leave. Caught between the ghost, a Native American runaway and the feared Whipman, the Ghostowners realize they may be walking into a trap.