Thereupon he took a curious box-shaped mechanism, pointed it at the Bird-Fairy, pressed a spring, and instantly the pretty trio became enveloped in a halo of rainbow. The next moment the wings of the Bird-Fairy drooped, and the children awoke. Her Spell was broken! He moved his terrible invention slightly, so that she alone was encircled by the rainbow ray. She stood there motionless like a beautiful statue; and the Bird-Fairy was in the Wizard's power! [Illustration: _The wizard, with a groan of pain, had leapt back_] A few moments more and his triumph would be supreme and everlasting. She would exist no more. His evil heart thumped with excitement and glee. A continuous and regular movement around the cave, and an underground heaving and low, distant rumbling arrested the Wizard's attention. He gasped and started, and the instrument he held fell from his grasp and shivered to atoms. The Twins were the cause. It was they who had started the commotion. Unobserved by the Wizard in his moment of exultation, freed by him from the Bird-Fairy's Spell, they were free to follow the irresistible inclination they felt when they were under it. So they gently stroked each of the animals around, and were charmed to find that as they did so each poor creature changed to girl or boy and vanished from its prison, whilst the ground trembled and the rumbling became louder and louder, as though some unseen power was helping in the rescue. So quickly did they run round on their task that at the moment when the Wizard realised his mishap, just as he thought he had triumphed, Dulcie and Cyril had done their work. They started as they saw the Wizard lying full length on the ground next to his shattered invention, the rays of which were let loose and playing like lightning all round him. Then they remained rooted to the spot with amazement, for just beyond was the Bird-Fairy, who before their astonished gaze became suddenly bereft of her wings and covering of feathers, and now stood before them as a lovely Princess, in draperies of silver tissue, and with a golden circlet upon her dark hair. A happy smile was on her face, as with a farewell gesture she motioned the children away. [Illustration: _Lying full length on the ground next to his shattered invention_] There was a terrific noise as of a thunder-clap. They looked back. Nothing but a dark cloud was there! * * * * * "Come quick!" cried Dulcie, taking Cyril's hand and running off with him; "there's no shelter here. Let's get in before the rain." And away they sped from the rocks on which they had so often played, reached home, ran indoors, and got upstairs just before the big drops turned into a heavy downpour and came pattering against the nursery window-pane. "Are you children ready?" called up their mother in her kind, cheery voice. "Come down and have tea with me for a treat."