"By this weapon of enchantment," said Fiacha, "you shall overcome the enchanter," and he taught Finn what to do with it when the hour of need should come.
So Finn took the spear, and left the strings of the case loose, and he paced with it towards night-fall around the ramparts of royal Tara.
And when he had once made the circuit of the rampart, and the light had now almost quite faded from the summer sky, and the wide low plains around the Hill of Tara were a sea of white mist, he heard far off in the deepening gloom the first notes of the fairy harp.

Never such music was made by mortal hand, for it had in it sorrows that man has never felt, and joys for which man has no name, and it seemed as if a man listening to that music might burst from time into eternity and be as one of the Immortals for evermore.

And Finn listened, amazed and rapt, till at last as the triumphant melody grew nearer and louder he saw dimly a Shadow Shape playing as it were on a harp, and coming swiftly towards him.

Then with a mighty effort he roused himself from dreams, and tore the cover from the spear-head and laid the metal to his brow.

And the demoniac energy that had been beaten into the blade by the hammers of unearthly craftsmen in ancient days thrilled through him and made him fighting-mad, and he rushed forward shouting his battle-cry, and swinging the spear aloft.