It occurred to him, while he was coaxing the intoxicating music from his instrument, that tonight would be midsummer night. Now was his chance to catch the Nixy's strain, for this exquisite violin would be capable of rendering the very chant of the archangels in the morning of time.

To-night he would surprise the Nixy, and the divine strain should no more drift like a melodious mist through his brain; for at midsummer night the Nixy always plays the loudest, and then, if ever, is the time to learn what he felt must be the highest secret of the musical art.

Hugging his Stradivarius close to his breast, to protect it from the damp night-air, Nils hurried through the birch woods down to the river. The moon was sailing calmly through a fleecy film of cloud, and a light mist hovered over the tops of the forest.

The fiery afterglow of the sunset still lingered in the air, though the sun had long been hidden, but the shadows of the trees were gaunt and dark, as in the light of the moon.

The sound of the cataract stole with a whispering rush through the underbrush, for the water was low at midsummer, and a good deal of it was diverted to the mill, which was working busily away, with its big water-wheel going round and round.

Nils paused close to the mill, and peered intently into the rushing current; but nothing appeared. Then he stole down to the river-bank, where he seated himself on a big stone, barely out of reach of the spray, which blew in gusts from the cataract. He sat for a long while motionless, gazing with rapt intentness at the struggling, foaming rapids, but he saw or heard nothing.

Then all of a sudden it seemed to him that the air began to vibrate faintly with a vague, captivating rhythm. Nils could hear his heart beat in his throat. With trembling eagerness he unwrapped the violin and raised it to his chin.

Now, surely, there was a note. It belonged on the A string. No, not there. On the E string, perhaps. But no, not there, either.