Pg. 401 of David Markson’s copy of The Complete Greek Drama: Volume One by Various (Ed. Whitney J. Oates & Eugene O’Neill, Jr.):

     On which Markson underlined most of the lines on the page in an exchange between Oedipus and Messenger in Sophocles’ Oedipus Rex (Oedipus the King).
     (And placed an X next to one line.)

—

     One of the lines underlined in the above scan is the Messenger saying to Oedipus:
     “Found thee in Cithaeron’s winding glens.”

     “Cithaeron.”
     Markson hauntingly brings up on pg. 117 of Reader’s Block with no other reference to the play in the general vicinity to give hint to meaning or to anchor one’s reading of the allusion.
     As is often the case with Markson…

     Markson is everything that is the case?