Detective John McClane (Bruce Willis) comes to Los Angeles from New York to meet his wife Holly (Bonnie Bedelia), whom he has not seen for six months. He is invited to a Christmas party on the 30th floor of a building. However, a group of gangsters set their sights on the more than 600 million yuan in government bonds stored in the building's vault. They block the building and take the partygoers hostage. McClane escapes by chance and fights the gangsters alone.