High in the untammed Adirondack Mountains lurks one of the most fiendish plots Frank and Joe Hardy have ever encountered. On a mission to rescue their good friend Holly from the cult of the lunatic Rajah, the boys unwittingly become the main event in one of the madman's deadly rituals -- human sacrifice.

Fleeing from the gun-wielding "religious" zealots and riding a danger-infested train through the wilderness, Frank and Joe arrive home to find the worst has happened. The rajah and his followers have invaded Bayport. As their hometown is about to go up in flames, the boys look to Holly for help. But Holly has plans of herown, and one deadly secret....