film critic,  François Truffaut (qv), Alfred Hitchcock (I) (qv) said: It might  be a Scottish name, taken from a story about two man in a train. One  man says "Whats that package up there in the baggage rack?" And the  other answers, "O thats a McGuffin." The first one asks "Whats a  McGuffin?" "Well" the other man says, "Its an apparatus for trapping  lions in the Scottish Highlands." The first man says, "But there are  no lions in the Scottish Highlands," and the other one answers "Well  then thats no McGuffin!" A McGuffin is nothing at all. Hitchcock  used the term to describe a device or plot element that catches the  viewers attention or drives the logic of the plot, especially in  suspense films. According to Hitchcock, the McGuffin can be ignored  as soon as it has served its purpose. Examples are the mistaken  identity at the beginning of _North by Northwest (1959)_ (qv) and  the entire Janet Leigh (qv) subplot of _Psycho (1960)_ (qv).