This door you might not open, and you did

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.