'...Bending their will to the task, The Four commanded the efreet to
  redouble their efforts, draining many of them thereby; the djinn howled
  with pain and sought to flee, but were drained of their magicks with a
  Word.  The Citadel was constructed before the Convergence took place;
  upon seeing it complete the slaves fell to slaying themselves and were
  devoured, screaming...'
                                          The Blood Scrolls