"Monsieur D'Estanges sends this, with his compliments," he said; and then Philip was again left alone.

Two hours after it became dark he thought he heard a confused sound, as of the trampling of a number of horsemen in the courtyard of the castle. He went to the door and, placing his ear against it, was convinced that he was not mistaken.

"That looks as if an expedition were about to start somewhere," he said. "If they are bound for Nerac, they will arrive there too late; for the queen will, by this time, be setting out. They cannot intend to scale the walls tonight, and the gates will have been shut long ago. They are probably going into ambush, somewhere near, so as to ride in in the morning.

"I wish I could be certain they are bound in that direction. There was certainly no idea of an expedition this morning, but it is possible that the messenger with the order for the arrest of the queen and prince may have arrived this afternoon, and the governor is losing no time.

"I trust it is so, and not that news has come, from some spy at Nerac, that she will leave the place tonight. If it is so, this party may be setting out to strengthen the guards on the river; or to occupy the roads by which she would travel, were her purpose to join the seneschal.

"I trust that Pierre and the others are on the alert, and not wasting their time in thinking about me; and that, if this troop make along the river, they will ride to warn the queen in time. Hearing nothing, she will assume that the road is clear, and that she can go on fearlessly.

"It is enough to drive one mad, being cooped up here when the whole success of the cause is at stake."

The character of the sentry's walk had changed. He had been relieved some four hours before, and his walk at times ceased, as if he were leaning against the wall to rest himself, while at times he gave an impatient stamp with his feet.

"I expect they have forgotten to relieve him," Philip said to himself. "If a strong body has gone out, that might very well be."

Another half hour passed, and then he heard steps ascending the stone staircase, and the sentry exclaimed angrily: