Edgar took up a small wooden box, through a hole in which the wire of the runner ran.  This evidently set some machinery in motion, for a sound as of whirring came.  From one side of the box floated what looked like a piece of stiff ribbon, which snapped and crackled as the wind took it.  For a few seconds Mimi saw it as it rushed along the sagging line to the kite.  When close to it, there was a loud crack, and a sudden light appeared to issue from every chink in the box.  Then a quick flame flashed along the snapping ribbon, which glowed with an intense light—­a light so great that the whole of the countryside around stood out against the background of black driving clouds.  For a few seconds the light remained, then suddenly disappeared in the blackness around.  It was simply a magnesium light, which had been fired by the mechanism within the box and carried up to the kite.  Edgar was in a state of tumultuous excitement, shouting and yelling at the top of his voice and dancing about like a lunatic.

This was more than Lady Arabella’s curious dual nature could stand—­the ghoulish element in her rose triumphant, and she abandoned all idea of marriage with Edgar Caswall, gloating fiendishly over the thought of revenge.

She must lure him to the White Worm’s hole—­but how?  She glanced around and quickly made up her mind.  The man’s whole thoughts were absorbed by his wonderful kite, which he was showing off, in order to fascinate her imaginary rival, Mimi.

On the instant she glided through the darkness to the wheel whereon the string of the kite was wound.  With deft fingers she unshipped this, took it with her, reeling out the wire as she went, thus keeping, in a way, in touch with the kite.  Then she glided swiftly to the wicket, through which she passed, locking the gate behind her as she went.

Down the turret stair she ran quickly, letting the wire run from the wheel which she carried carefully, and, passing out of the hall door, hurried down the avenue with all her speed.  She soon reached her own gate, ran down the avenue, and with her key opened the iron door leading to the well-hole.

She felt well satisfied with herself.  All her plans were maturing, or had already matured.  The Master of Castra Regis was within her grasp.  The woman whose interference she had feared, Lilla Watford, was dead.  Truly, all was well, and she felt that she might pause a while and rest.  She tore off her clothes, with feverish fingers, and in full enjoyment of her natural freedom, stretched her slim figure in animal delight.  Then she lay down on the sofa—­to await her victim!  Edgar Caswall’s life blood would more than satisfy her for some time to come.

CHAPTER XXVIII—­THE BREAKING OF THE STORM

When Lady Arabella had crept away in her usual noiseless fashion, the two others remained for a while in their places on the turret roof:  Caswall because he had nothing to say, Mimi because she had much to say and wished to put her thoughts in order.  For quite a while—­which seemed interminable—­silence reigned between them.  At last Mimi made a beginning—­she had made up her mind how to act.