John McClane learns that his son Jack, to whom he hasn't spoken in years, is in Russia and was arrested for killing someone. When the Russian prosecutor talks to Jack he claims to have information that could help convict a man named Komarov who is going to be tried. McClane arrives and proceeds to the Russian courthouse where Komarov's going to be tried. When he arrives there's an explosion that levels the courthouse. Jack takes Komarov and they escape, McClane shows up and Jack is not happy to see him. The men who bomb the courthouse chase Jack. McClane follows and helps Jack. Jack then picks him up then they go somewhere, where McClane discovers that Jack is a spy and he was suppose to get Komarov because it seems he has evidence against a corrupt Russian official who was behind the bombing. When he agrees to give them the evidence in exchange for his freedom and daughter's, the men find them. So McClane and Jack have to get the evidence and get out of Russia. When they go to meet the man's daughter, McClane senses something is not right.