Question: Several times in the movie one character is able to ascertain in which hotel room another character is staying simply by asking the front desk for the room number. Was this realistic at the time the movie was made? Today, a hotel would never divulge a guest's room number to a stranger, since such information could potentially be used by burglars and/or predators to gain access to hotel rooms. Was security really that lax in the 1950s?
Answer: Yes, security was that lax in the 1950s and beyond. People could acquire all kinds of information about individuals from various types of businesses. Not all were so careless, but many were or they naively didn't see a concern. In the late 1980s, I was a student at a university where a non-university person obtained his ex-girlfriend's class schedule simply by requesting it in-person from the registrar's office. Using that information, he was able to locate and fatally shoot her on campus.
Question: Why is this movie called 'North by Northwest'?
Chosen answer: The original title for the movie was "In a Northwesterly Direction", as it was originally detailing the flight of a man from New York to Alaska, according to writer Earnest Lehman. According to Alfred Hitchcock, however, he took the title from a line in Hamlet, another work of fiction that is concerned with the slippery nature of reality. It is also worth noting that North by Northwest is not a direction on the compass at all. The nearest to it would be Northwest by North.
Question: Why do the kidnappers take Thornhill to the Townsend home and pretend to be Lester Townsend and members of his household? They could have taken him to some obscure place instead, at less risk of being found out.
Answer: More than likely, they felt that Roger would be dead and they would not be found out. The fact that he survives their DUI plot and returns to the house with the police only serves to makes him look more suspicious and guilty. It's to move the plot along, nothing more.
The bigger plot hole is, if Van Dam really believes Roger is Kaplan, why would he think that Roger would bring the police and go through the trouble of preparing "Mrs. Kaplan" to make the police think he's crazy? If Roger really was a spy, he doesn't need help from the police and would have just disappeared instead of retracing his steps. So if Van Dam anticipated the actions taken by Roger, he must believe at some level that Roger is telling the truth and would have looked deeper into it.
Question: Who is the beautiful woman sitting to the left of Gary Grant in the art auction scene?
Answer: She's just a an auction attendee who happens to be sitting next to Roger Thornhill. They do not know each other.
Answer: Not really. You could (and at some hotels are still able to) keep your room number private or you could not - i.e. you could ask the hotel staff to keep your number secret from strangers, or you could ask them to tell anyone who might ask. Not having seen this movie, I don't know how likely it would be in the situations you speak of that the hotel guest would choose the latter option- it might be a mistake.
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