And then he became silent again, watching Clif. He seemed to be very much interested in him, from the way he studied the American's face. And once he gave a slight sigh.
Clif looked at him in surprise; but the man turned away, and he went toward the door.
"I will return soon," said he, again in that quiet, firm voice. "Wait here."
There was nothing for Clif to do but wait; for when the door shut he was locked in the cell.
That man's action was a mysterious one indeed. It left the cadet plenty to think of. He saw now where he got the keys. He was evidently one of the officers in charge of the castle.
But why had he done it? Clif was utterly baffled before that question.
But it was not for very long; he soon learned, and in a startling and unexpected way.
Clif had not noticed it, but there was another door to that cell. It was behind him, leading to a small room in the rear.
While he stood there motionless and lost in thought waiting for the Spaniard's return, that door was silently opened, and a figure stood watching him.
And then suddenly it stepped out and came across the room.