Developing the Character of John Galt

     As I continue to read the novel, the phrase "Who is John Galt?" continues to appear various times through many characters. Only on two occasions have explanations been given when the phrase comes up: once at Rearden's party, when a lady claims that she knows someone who knows John Galt personally and has seen him discover the underwater city of Atlantis, and then again at the diner, when Dagny is told that John Galt spent years searching for the Fountain Of Youth, and successfully accomplished it after several tries.
      As the plot continues to unravel, I began to realize that John Galt may be more than just a hypothetical phrase, and might be closer in person to all the characters, even if they are not aware of it. For example, through out the novel we have two instances so far where two unknown characters are presented. Fransisco's professor tells us how he had three students, Fransisco d'Anconia, Ragner Danneskjold, and another student that remains nameless, which supposedly disappeared from society. Then we have that late night encounter that Dagny has in her office with a shadow that struggles to decide whether to enter Dagny's office or not. Once that unknown shadow decides not to enter, Dagny runs out of her office to see who the mystery shadow is, but the shadow is gone and it is too late.
     I believe that this "mystery" character that continues to appear may have something to do with John Galt, or it could be him personally. Once Dagny tells Fransisco about the name of the new line, "The John Galt", Fransisco tells Dagny that John Galt will come to claim his line, which could have been that shadow figure to appear at Dagnys office late at night. Fransisco's professor tells us how he had that one student who just disappeared, which could have also been John Galt considering that he was a an intellectual man, and had removed himself from society in order to search for the Fountain of Youth or Atlantis, meaning that he would have also had studied with Fransisco, so Fransisco would know what he means when he says that John Galt would claim the new line that Dagny was working on.