The Castlemans did not offer to move, but Yolanda, springing to her feet, said, “Come,” and led the way.

The upper end of the garden, as I have told you, was on the banks of the Cologne at a point where it flowed into the castle moat.  The castle wall, sixty feet high at that point, bordered the west side of the garden.  The moat curved along the right side, and the river flowed past the upper end.  Castleman’s house faced south, and stood on the lower end of the strip of ground that lay between the castle wall and the moat.  The Postern was perhaps three hundred yards north from the upper end of Castleman’s garden.  Since it was on the opposite side of the river, one could reach the Postern, from Castleman’s house, only by going up to the town bridge and back to the castle by the street that followed the north side of the Cologne.

We all walked to the upper end of the garden, and stood leaning against the low stone wall at the river’s edge.  We had waited perhaps ten minutes when we heard a blare of trumpets and saw a small cavalcade of ladies and gentlemen ride from the castle and pass over the drawbridge.

“The lady in scarlet is the duchess,” said Castleman.

“She is English,” remarked Yolanda, “and loves bright colors.”

“Which is the princess?” I asked of Yolanda, feeling that I also was acting my part admirably.  To my surprise she answered promptly:—­

“She in blue with a falcon on her shoulder.  Am I not right, uncle?”

“Yes,” responded Castleman.  Twonette confirmed the statement.

My air-castles fell noiselessly about my head.  My dreams vanished like breath from a cold mirror, and the sphinx-like face of my great riddle rose before me in defiance.

After the cavalcade had passed I found myself with Yolanda a dozen paces from the others.

“Fraeulein,” I said, “I want to confess I thought you were the Princess Mary of Burgundy.”

Yolanda laughed softly.

“I was sure you had some such absurd notion.  I supposed you had seen her, and had believed she was Yolanda, the burgher girl; that mistake has often been made.  You may see this princess at the castle, and I warn you not to be deceived.  I have the great honor, it is said, to resemble Her Highness as one pea resembles another.  I have been told that she has heard of the low-born maiden that dares to have a face like hers, and she doubtless hates me for it, just as I bear her no good-will for the same reason.  When two women greatly resemble each other, there is seldom good feeling between them.  Each believes the other is stealing something of her personality, and a woman’s vanity prompts her to resent it.  If you make the mistake with the princess that you made with me, I warn you it will not be so easily corrected.”