What is a MacGuffin

MacGuffin was created by Alfred Hitchcock it can be referred as a hidden catalyst which moves the plot on to create scene or ending with a twist. It can also be referred as the engine that sets the story in motion. It can be anything or nothing at all. In The 39 Steps, it is "secrets vital to your air defence"; in Number Seventeen it is a valuable piece of jewellery, while in The Lady Vanishes it is, in the most perfectly abstract of all Hitchcock's MacGuffins, a coded message contained in a piece of music. Examples of these are in the films such as:

• The top secret plans in The 39 Steps (1935).
• The eponymous statuette in The Maltese Falcon (1941)
• The letters of transit in Casablanca (1942)
• The uranium in Notorious (1946)
• The case with glowing contents in Kiss Me Deadly (1955)
• The "government secrets" in North by Northwest (1959)
• The stolen $40,000 in Psycho (1960).
• The stamps in Charade (1963)
• The Death Star plans in Star Wars Episode IV: A New Hope (1977)
• The Ark of the Covenant in the first Indiana Jones film, Raiders of the Lost Ark (1981)
• The unknown, glowing contents of the briefcase in Pulp Fiction (1994).
• The Rabbit's Foot in Mission: Impossible III (2006)
• The chest in Pirates of the Caribbean: Dead Man's Chest (2006).
• The Allspark in Transformers (2007).
• The Russian painting in RocknRolla (2008).
• The sculpted head from Ponte Santa Trinita in Miracle at St. Anna (2008)
• The silver briefcase in Jack Said (2009)
• The unobtanium in Avatar (2009)