In the mean while, the dwarf Alberich has conveyed the gleaming Rhinegold to his underground dwelling, where, mindful of the nymphs’ words, he has forced his brother and slave, the smith Mime, to fashion a ring.  No sooner has Alberich put on this trinket than he finds himself endowed with unlimited power, which he uses to oppress all his race, and to pile up a mighty hoard, for the greed of gold has now filled all his thoughts.  Fearful lest any one should wrest the precious ring from him, he next directs Mime to make a helmet of gold, the magic tarn-helm, which will render the wearer invisible.  Mime is at work at his underground forge, and has just finished the helmet which he intends to appropriate to his own use to escape thraldom, when Alberich suddenly appears, snatches it from his trembling hand, and, placing it upon his head, becomes invisible to all.  The malicious dwarf misuses this power to torture Mime with his whip, and rushes off to lash the dwarfs in the rear of the cave as Wotan and Loge suddenly appear.  Of course their first impulse is to inquire the cause of Mime’s writhing and bitter cries, and from him they hear how Alberich has become lord of the Nibelungs by the might of his ring and magic helmet.  In corroboration of this statement, the gods soon behold a long train of dwarfs toiling across the cave, bending beneath their burdens of gold and precious stones, and driven incessantly onward by Alberich’s whip, which he plies with merciless vigour.  He is visible now, for he has hung the magic helmet to his belt; but he no sooner becomes aware of the gods’ presence than he strides up to them, and haughtily demands their name and business.  Disarmed a little by Wotan’s answer, that they have heard of his new might and have come to ascertain whether the accounts were true, Alberich boasts of his power to compel all to bow before his will, and says he can even change his form, thanks to his magic helmet.  At Loge’s urgent request, the dwarf then gives them an exhibition of his power by changing himself first into a huge loathsome dragon, and next into a repulsive toad.  While in this shape he is made captive by the gods, deprived of his tarn-helm, and compelled to surrender his hoard as the price of his liberty.  Before departing, Wotan even wrests from his grasp the golden ring, to which he desperately clings, for he knows that as long as it remains in his possession he will have the power to collect more gold.  In his rage at being deprived of it, Alberich hurls his curse after the gods, declaring the ring will ever bring death and destruction to the possessor:—­

   ’As by curse I found it first,
    A curse rest on the ring! 
    Gave its gold
    To me measureless might,
    Now deal its wonder
    Death where it is worn!’