Bluebeard by Edna St. Vincent Millay

This door you might not open, and you did;
  So enter now, and see for what slight thing
You are betrayed. . . .  Here is no treasure hid,
  No cauldron, no clear crystal mirroring
The sought-for truth, no heads of women slain
  For greed like yours, no writhings of distress,
But only what you see. . . .  Look yet again --
  An empty room, cobwebbed and comfortless.
Yet this alone out of my life I kept
  Unto myself, lest any know me quite;
And you did so profane me when you crept
  Unto the threshold of this room to-night
That I must never more behold your face.
  This now is yours.  I seek another place.