Local recluse Neil Bedey harbors a generations-deep hatred for Yellowstone National Park. His plan for revenge? To set free enormous killer ravens contained in the park’s interior, put thousands of visitors’ lives in jeopardy, and force the park closed forever. National Park Service rangers Kathy West and Nathan Toland have the clandestine mission to keep dangerous creatures in the park at bay. When several large animals are killed with ferocious savagery, and then two hikers vanish, Kathy is sure another secret National Park monster is on the loose. Nathan’s research uncovers how a secret society first contained the threat. But Bedey is several steps ahead of them, aided by traitorous conspirators within the park, and international help from without. Last time, it took the U.S Army to defeat the ravens. Will the rangers beat the odds and stop the impending reign of terror by the ravens of Yellowstone?