Although the film (re-titled Die Hard) was altered to be a stand-alone film with no connections to Thorp's novel, and does not follow the source material very closely, some of its memorable scenes, characters, and dialogue are adapted directly from the book. Some of the biggest changes in the film included the older hero of the novel becoming 25 years younger, his name changed from "Joe Leland" to "John McClane", the person he is in the skyscraper to visit changing from his daughter to his estranged wife, and the American "Klaxon Oil Corporation" becoming the Japanese "Nakatomi Corporation". The "terrorists" in the film are actually professional thieves that are after $640 million in negotiable bearer bonds kept in the building's vault and are only posing as terrorists to draw attention away from the robbery.