Psycho

Psycho is a 1960 Alfred Hitchcock film starring Anthony Perkins, Vera Miles, John Gavin and Janet Leigh. At first the film starts with Vera Miles (Marion Crane) who tries to escape with running off with &40,000 of her bosses money, the audience is led to believe that the film will be about a runaway of a woman who may potentially be the psycho. However, a huge twist is taken when the Marion is killed while staying at a motel by 'the mother' of the man- Anthony Perkins (Norman Bates) in the shower, leading the the ever famous 'shower scene' in film history.
Marion's death comes from no-where, after chatting with Norman on arriving at the inn, he asks her for dinner, however we can hear (diegetic) him having a 'conversation' with his mother who frowns and disregards Marion and other unknown girls, Norman apologizes for his mother not allowing her to eat with them in their house, however he brings her some food to eat and talk with him in his study. Norman's study is crucial to the mise-en-scene, and topic of conversation. The room includes stuffed birds of prey such as owls along with portraits of naked women; it is not fact but it leads us to suspect what kind of character Norman may be, one of a perving and dominating individual that likes to stalk vulnerable woman.
Coming back to the shower scene analysis shows that it marks as a terrorising moment in horror history at the time, as today in cinema and film we are given the gore, the violence and nothing is really left for us to imagine what happens as we see all the terror on screen, however the horror genre in the 60's was fairly new and for the audience to imagine what happens to Marion in the shower scene is as terrorising as their imagination sees it, which we can try to relate to as being something scary or terrorising, but being the children of today that we are, and seeing movies of our age and the media, we are given all the gore so nothing is left to the imagination, and we believe that our movies and horror films are more scary.
The amazing twist comes at the end of the film where it is reveled that the mother who kills Marion and the private investigator is Norman himself (the Psycho) where it comes apparent as Norman's psychological analysis revels that he has taken on his mums personality and his own,  where Norman likes and crushes on girls such as Marion his brain believes that his mother is jealous of the girl and because his 'mother' part of his brain is jealous she kills them,  more than your average personality disorder.
The Mcmuffin plays a part (being that the money), unknown to Norman it is buried with Marion in the swamp, in which when his 'mother' kills Marion, as an audience it is at this point still unknown that Norman actually hosts two personalities, and as the money is buried with Marion, it shows us how incredibly sneaky a macguffin can be in hiding itself as a 'macguffin', at the beginning we believe that the money is the main crucial element of story line, however as the killings start, it is unconsciously made aware to us that the money was all along a mcguffin, a crucial piece of the film that is credit to Hitchcock's amazing work, even in today's day and age where we are seen as naive and arrogant to earlier film and media work, you cannot deny the work that Hitchcock has produced in terms like Psycho.