The dreamer goes in search of this lost person or object.
The dreamer searches low and high, running through all the lifeless streets. When the object is found (often it isn't really found, or it is found under some absurd transformation) the dreamer returns to the doors of the gathering place, but the doors are locked or they are barred by a polite official. This person, who for both Macarthur and Urquhart is always Richard Milhous Nixon, will not let the dreamer take in that which has been left behind.
Like everyone else who has this dream, Urquhart and Macarthur know perfectly well what it is about.