Not the less did he keep his eye on the tower-side of the moat, and had not swum far before he caught sight of the little stair, which, enclosed in one of the six small round bastions encircling it, led up from the moat to the walk immediately around the citadel.  The foot of this stair was, strangely enough, one of the only two points in the defence of the moat not absolutely commanded from either one or the other of the two gates of the castle.  The top of the stair, however, was visible from one extreme point over the western gate, and the moment Richard, finding the small thick iron-studded door open, put his head out of the bastion, he caught sight of a warder far away, against the moonlit sky.  All of the castle except the spot where that man stood, was hidden by the near bulk of the keep.  He drew back, and sat down on the top of the stair—­to think and let the water run from his clothes.  When he issued, it was again on all-fours.  He had, however, only to creep an inch or two to the right to be covered by one of the angles of the tower.

But this shelter was merely momentary, for he must go round the tower in search of some way to reach the courts beyond; and no sooner had he passed the next angle than he found himself within sight of one of the towers of the main entrance.  Dropping once more on his hands and knees he crept slowly along, as close as he could squeeze to the root of the wall, and when he rounded the next angle, was in the shadow of the keep, while he had but to cross the walk to be covered by the parapet on the edge of the moat.  This he did, and having crept round the curve of the next bastion, was just beginning to fear lest he should find only a lifted drawbridge, and have to take to the water again, when he came to the stone bridge.

It was well for him that Dorothy and Caspar had now omitted the setting of their water-trap, otherwise he would have entered the fountain court in a manner unfavourable to his project.  As it was, he got over in safety, never ceasing his slow crawl until he found himself in the archway.  Here he stood up, straightened his limbs, went through a few gymnastics, as silent as energetic, to send the blood through his chilled veins, and the next moment was again on the move.

Peering from the mouth of the archway, he saw to his left the fountain court, with the gleaming head of the great horse rising out of the sea of shadow into the moonlight, and knew where he was.  Next he discovered close to him on his right an open door into a dim space, and knew that he was looking into the great hall.  Opposite the door glimmered the large bay window of which Mrs. Rees had spoken.

There was now a point to be ascertained ere he could determine at which of the two gates he should attempt his exit—­a question which, up to the said point, he had thoroughly considered on his way.