But Bettina looked eagerly at Marianne.
"Gracious, Fräulein," she said, "when will Frederick Barbarossa awake? I am always telling the ravens."
Before Marianne could reply Carl jumped from his seat, the twins started up in fright.
A sharp knock had sounded on the window.
"What is it, sister?" And the twins ran to Marianne.
At that moment the Professor came in at the door.
"Nonsense," he said; "who could be at our window?"
But the children insisted.
"We heard it, father," they said.
The Professor, crossing the room, opened the sash, the children following.