The old woman looked at her kindly.

“I knew from the first that thou wert a maid disguised,” she said.  “Go, and God speed you!  Tell the knight of Windeck that the people of Strassburg mean to attack his castle on the morrow, and that his only means of resisting them is to dig a deep trench across the one possible approach.  But stay—­there is no time for that; I will give you something wherewith to dig the trench.”

She whistled shrilly and in answer to her call a grey hen fluttered toward her; this she gave to the young people.  “When the moon rises,” she said, “take the hen and place it where you wish the trench to be.”

Then with a few words to the hen in a strange tongue, she bade the brother and sister farewell and went on her way.

The two continued their journey and upon arriving at Windeck they were agreeably surprised in the lord of the castle, for he was young and handsome and very courteous, not at all the ogre they had imagined.  In faltering tones Imma told him their mission, conveyed to him the old witch’s warning, and presented the grey hen.

When he heard that they proposed to gain their uncle’s freedom by themselves taking his place, the knight regarded his visitors with mingled feelings of pity and astonishment.  The gentle, appealing glance of the elder, no less than the naive candour of the younger, appealed to his sympathies.  In a very short time Cuno, who had quite forgotten to challenge his host, was on the best of terms with him.

Meanwhile the Dean, very impatient and incensed, paced his small chamber like a caged lion, or bemoaned his lost liberty and meditated on the chances of escape.  He was roused from a reverie by the sound of familiar voices outside his cell, and a moment later the door was flung open and Cuno entered unceremoniously.

“You are free, uncle, you are free!  Imma and I have come to save you!”

Once more Imma flushed crimson at the revelation of her sex.  The astonished knight glanced with a new interest at her beautiful face, with its rosy colour and downcast eyes.  Turning to the Dean, he greeted him cordially.

“You are free,” he said.  “Your nephews have promised to remain with me as hostages till you have provided a ransom,” Then, turning humorously to Imma, he added:  “Wilt thou be a soldier in my employ, youth?  Or wouldst have a place in my household?”

Imma vouchsafed no other reply than a deepening of her colour.  She must, however, have found words to utter when, later, the gallant knight begged her seriously to remain at Windeck as his wife—­for ere nightfall the old Dean, grumbling and somewhat reluctant, was called upon to consent to his niece’s betrothal.  This he did at length, when Imma had joined her entreaties to those of her lover.

That night the grey hen was placed as the witch had advised, and it was as she had said.  With the dawn the Strassburgers arrived before the castle, to find a newly made trench filled with the castle troopers.  When they learned that the Dean was free they called for a truce, and it was not blood, but wine, which flowed that day, for all were invited to share the wedding-feast of Imma and the knight of Windeck.