NYPD Detective John McClane has faced some brutal terrorists in his career, but now, he's about to face what may be his most dangerous enemy yet. John, who occasionally does work for the U.S. Department of Homeland Security, receives a call to bring in a hacker named Matt Farrell, because there has been a breach in an FBI computer system. Farrell is one of the many hackers who are suspected in the attack. After John gets to Matt's apartment, men show...