Did these ladies creep you out or what? They seem to represent the Moirae or the Fates as envisioned by the ancient Greeks. Two of the three Fates spin the life-thread of each human being. The thread represents a human life. The third Fate cuts the thread when the time comes for the man to die. The Fates, being immortals, have foresight and thus can see every man’s fate. Conrad uses the two women knitting black wool as foreshadowing for Marlow’s horrific journey into the interior. Yes, we too are wondering what happened to the third Fate.