MacGuffin
McGuffin (aka: MacGuffin or maguffin) is a term for a PlotEnablingDevice, i.e. a device or plot element in a movie that is deliberately placed to catch the viewer's attention and/or drive the logic of the plot, but which actually serves no further purpose - it won't pop up again later, it won't explain the ending, it won't actually do anything except possibly distract you while you try to figure out its significance. More specifically, it is usually a mysterious package or superweapon or something that everyone in the story is chasing.
It is the money taken from the boss in "Psycho"
it is the suitcase in "Ronin"
McGuffin (aka: MacGuffin or maguffin) is a term for a PlotEnablingDevice, i.e. a device or plot element in a movie that is deliberately placed to catch the viewer's attention and/or drive the logic of the plot, but which actually serves no further purpose - it won't pop up again later, it won't explain the ending, it won't actually do anything except possibly distract you while you try to figure out its significance. More specifically, it is usually a mysterious package or superweapon or something that everyone in the story is chasing.
It is the money taken from the boss in "Psycho"
it is the suitcase in "Ronin"