"The famous MacGuffin , the Hitchockian object, the pure pretext whose sole role is to set the story in motion but which is in itself nothing at all - the only significance of the MacGuffin lies in the fact that it has some significance for the characters - that it must seem to be of vital importance to them... - that's a MacGuffin, a pure nothing which is non the less efficient... what Lacan calls object petit a: a pure void which functions as the object cause of desire."