Our intrepid heroes, Josh and Mac, together with their friend Mark, are drawn deeper into the mystery of the tunnels beneath Niagara Falls. As the tunnels begin to reveal more of their dark, long buried secrets, the trio discovers the truth about the dreadful events of the past, and about the cruel leader and his followers who used the tunnels for pure evil… Following the historic timeline, they travel to Europe looking for answers. Worlds collide as past horrors come to light. Clues unearthed in Germany and Italy point straight back to the tunnels of Niagara, but the tunnels do not give up their secrets easily, and danger is never far away… The events of the past may yet have a catastrophic impact on the lives of Josh, his friends and their families unless they act quickly. The odds of survival, let alone solving the mystery, seem overwhelming…