She did not answer him, neither did she come; but he had a strong conviction that she heard.  A throb of anger went through him.  He strode forward with decision.  He knew that the battlement walk ended on the north side of the Castle in a blank wall, built centuries before as a final defence from an invading enemy.  Only by scaling this wall could the eastern portion be approached.  He would find her here.  She could not possibly escape.  Something of confidence came back to him as he remembered this.  She could not elude him much longer.

He quickened his stride.  His face was grim.  She had carried the thing too far, and he would let her know it.  He rounded the curve of the castle wall.  He must be close to her now.  And then suddenly he stopped dead.  For he heard her mocking laughter, and it came from behind him, from the turret through which he had gained the ramparts.

He wheeled round with something like violence and began to retrace his steps.  He had never been so baffled before, and he was angry,—­hotly angry.

He rounded the curve once more, and approached the turret.  His eyes were accustomed to the dim half-light, but still he could not see her.  Fuming, he went back the whole distance along the ramparts till he came to the iron-clamped door that had banged behind him.  He put forth an impatient hand to open it, for it was obvious that she must have eluded him by hiding behind it, and now she was probably on the stair.  And then, very suddenly, from far behind him, in the direction of the northern wall, he heard her laugh again.

He swung about in a fury, almost too incensed to be amazed.  She had the wings of a Mercury, it was evident; but he would catch her—­he would catch her now, or perish in the attempt.  Once more he traversed the stony promenade between the double line of battlements, searching each embrasure as he went.

All the way back to the wall on the north side he pursued his way with fierce intention, inwardly raging, outwardly calm.  He reached the obstructing wall, and found nothing.  The emptiness came all about him again.  The ghostly quiet of the place clung like a tangible veil.  She had evaded him again.  He was powerless.

But at that point his wrath suddenly burst into flame, the hotter and the fiercer for its long restraint.  He wheeled in his tracks with furious finality and abandoned his quest.

His intention was to go straight down by the way he had come and leave her to play her will-o’-the-wisp game in solitude.  It would soon pall upon her, he was assured; but in any case he would no longer dance to her piping.  She had fooled him to the verge of frenzy.

Again he rounded the curve of the wall and came to the door of the turret.  A great bastion of stone rose beside this, and as he reached it a small white figure darted forward from its shadow with dainty, butterfly movements, pulled at the heavy oak door and held it open with an elaborate gesture for him to pass.