As the McClane saga continues, the family is forced to aid General Robert McClane in his travels to Fort Knox where he will meet up with the rest of his people from the bunker. The strength of the group will be tested, and hard choices met head-on.The family will face a new threat in the area that is wiping out innocent people near their farm, and some will be put in perilous situations. Cory and Paige will need to confront a difficult decision of their own, but can she let go of her fears to do so?Sam has given up all hope that Simon will come to his senses, but has he given up on her and is he willing to let her go so easily?And a fight for survival none of them saw coming will knock on their door. Can the family survive their toughest adversary yet?