Melkor undergoes a name change throughout the series from this point because he did so in canon.
Angwë made his way to Angband. He knew it was somewhere north of where he was, and that all he had to do to find it was to keep heading north and follow any trail of destruction he should find on the way. He did not rush, but took his time in his journey. Therefore he had time to notice the Men, the Second-born, who had made their appearance on Middle Earth.
They looked to be similar to the Elves in many ways, but as he drifted by in his disembodied state, he was able to listen in to their conversations and see a little of their lifestyles. They had already heard of the Dwarves and the Elves. Indeed, they had already been befriended by Finrod Felagund, and could speak Sindarin fluently. They used it not only to speak with the Elves, he discovered, but also to exclude others when desiring to keep a conversation private. Sometimes Angwë felt a bit guilty for eavesdropping in this way, but when he considered the other things he believed himself to be culpable of, he decided it was just a little matter and would most likely not be noticed anyway. He dwelt unseen among Men for some years, learning their language and customs, and seeking information he could use for his own benefit. This he would use when treating with Sauron and Melkor, as he did not want to simply become a puppet for them.
It was as the first generation of Men that Angwë had been watching began to succumb to old age, he decided to move on. He had heard rumours that there had been some fighting to the west, quite close to where he was in East Beleriand. Orcs, it seemed, had been breeding and had started to penetrate deep into territories held by the Elves of various tribes. This was causing them to unite in their efforts to drive this menace away from their lands, and Angwë realised this could only mean trouble. Having spent so much time with Dwarves and Men, Angwë knew first hand of their capabilities. Given that Dwarves and Elves were freely sharing their knowledge and technologies with Men, it was only a matter of time before they would be able to lay siege to Angband itself. If this should happen, he reminded himself, there would be no aid to ask for from Sauron or Melkor, as they would be too preoccupied with their own concerns to trouble themselves about him or his mountain.
He made his decision: it was time for him to leave. As quickly as he could, he sought out the bands of Orcs and worked his way to Angband through them. As he arrived in the foothills of the Iron Mountains, he beheld the desolation and trembled. Was this the fate he had chosen? To house with the freaks and monsters Melkor and Sauron had created and there await his doom? No, he reminded himself, he was going to use the two most evil beings he knew to aid him in the regaining of control over the mountain he had made. This would, of course, involve his taking part in deplorable acts on the way, but that could not be helped. There was no way anyone else would help him, after all.
Resolutely he marched up the rocky path to the gates, which at this point were ajar as Orcs and other creatures scurried to and fro under the cover of the darkness provided by Ered Engrin as it spewed forth smoke and ash in the throes of its fury. Clouds of ash and smoke circled above it, and streams of lava constantly flowed down its flanks. He hesitated for a moment. Was there definitely no way to be reconciled with his master Aulë? After all, when Melkor had "repented," he had been welcomed back in Valinor. As he considered his position, he remembered that Aulë had created the Dwarves that had so angered him, and that he had made them to be miners. He had even permitted Angwë to style himself Khaghar, Lord of Miners, to help keep them safe in the mines. There was no way Aulë would ever permit Angwë to prevent the Dwarves from digging wherever they pleased in search of treasure. Angwë knew that the idea that anyone could own the mountain he had made seemed foolish to Aulë, who gave freely of his own inventions. Clearly, he expected his disciple to feel the same way. Well, Angwë was having none of it. He had made that mountain, and it was his and his alone. Gathering his courage, Angwë entered the gates of Angband.
Sauron stood brooding at the gates of Angband watching the Orcs and other monsters as they came and went. The reports he had received of the changes to the world disturbed him, and he was concerned that the reign of his master Morgoth might be threatened by the advent of the new lights, the Sun and Moon. What next? Would the Valar return and fight them again? What would they do this time? If only more Maiar would join them!
He thought of Angwë. He had tried so hard to persuade him to abandon whatever fealty he felt towards Aulë and the other Valar by prodding at his insecurities! Angwë cared more for the mountain he had made than anything else. Sauron hoped that if he kept reminding him that the Valar cared nothing for Angwë's sense of entitlement and ownership of it, and believed the Dwarves had a right to go mining there if they so desired, sooner or later he would come to Angband seeking aid. Thus far his brother had proved to be very stubborn, but he had sensed his frustration at his failure to control the Dwarves and make them stop mining there when he was holding the spirit of Adzarek captive. One more push ought to do it, but it had to be done at the right time, or he would fail again.
Of course, if Angwë should succeed in driving them out by himself, all his efforts would come to naught, but Sauron had ways of ensuring that the Dwarves truly believed in their right to go mining where they would. If Angwë ever found out about this, there would be trouble, but Sauron was subtle and knew how to cover his tracks.
A shout from the guards at the gates caught his attention, and Sauron went over to see what the matter was. He was not surprised to see who was there, demanding to be taken to the lord of the realm.
“I have come to see Morgoth,” said Angwë belligerently, as the guards refused him entry
"Angwë, my brother!" Sauron trilled. "Welcome to Angband! So what has finally brought you here? Have those pestilential Dwarves finally destroyed that mountain you worked so hard at building?" He turned to the guards. “Let him in.”
"Do not mock me, Sauron!" Angwë snarled, making his way towards his brother. "I am filled with a fell wrath, and will smite you if I am further provoked."
"My brother, I am sorry. Not till now have I realised how much that mountain meant to you. What has brought you here?" Sauron asked solicitously as he led his brother into the main hallway.
"I appeared to one of them in a dream," Angwë explained in calmer tones, walking alongside him, "and he tried to obey me but ended up making things worse. I wandered in East Beleriand, seeking this place, but slowly. As I made my way, I discovered the Second-born, who are even now abroad and in contact with the Elves and the Dwarves. They are in league with each other and there is talk of joining with the folk of Fingolfin brother of Fëanor in order to oppose you. Those who did not make the Great journey to Valinor are being allowed to believe that Fëanor and his people have come here to protect them from you."
"Why are you telling me this?" Sauron asked, trying not to sound too anxious. The thought of a united assault was terrifying. While neither he nor Morgoth could be actually killed, they could be dealt serious blows that could either seriously limit them or even imprison them in a kind of living death that both of them feared greatly. Sauron had no desire to share such a fate with his master.
"I thought to join with you, though I opposed you before," Angwë told him, "because I am now in opposition to Aulë who was my master, but is not any more."
"This is because it is as I had told you," Sauron said gently, trying not to gloat overmuch, "Your efforts were for the Dwarves, not for yourself. You had no will of your own, you were but a servant, a mockery of what you could have been."
"I can see that now," Angwë agreed, "when will I be brought before Morgoth?"
"I need to persuade him." Sauron explained, "He will not agree to meet you until you have proved both your worth and your loyalty. There are some tests you will face first. I will help you where I can. First of all, when you speak to him, you must use the Archaic form, and wait until he has spoken to you first. He will not tolerate any modernisms. He insists on being addressed in this way at all times. Now come with me, I must bring you to the Chamber of Awaiting. Since our Lord expects obedience, you must wait there until he calls for you, even if it is for a thousand years."
The corridors of Angband were dark, gloomy and stank of damp, blood and sweat. Muffled cries, screams and roars could be heard faintly echoing in the distance. Smoke from the torches and lamps that stood on shelves and in brackets filled the stale air as Sauron led his brother to the Chamber of Awaiting and locked the door. Angwë started when he did this, but remembered that this was a test of obedience. To attempt to escape or to shout until he got an answer was to prove himself impatient, mistrusting and ultimately untrustworthy. He bit back any comments he might have made and waited upon his new master's pleasure.
It was during the one hundred and fiftieth year of his waiting that Angwë was finally brought to meet his new master. Remembering what his brother Sauron had told him, he waited for Morgoth to speak first.
"I greet thee, Angwë," Morgoth began, "and welcome thee to Angband, which thy brother Sauron long held in keeping for me. Thou hast passed the first test, seeking not to be released until it should please me to do so."
Angwë was silent. This was the first time he had beheld Morgoth since he saw him in Valinor before the War of the Powers, and he now looked very different. Then, he was huge and powerful, and beautiful to look upon. Now he was hunched and withered, a shadow of what he had been before, and terrible to look upon. Shock and horror overwhelmed Angwë as he gazed upon his new master, trying to find a reason not to turn tail and run. How could he serve a master who was evidently so twisted up with rage and hatred he appeared to be torturing himself? He was wearing a crown with three bright jewels on, and it appeared to be burning his forehead. Why did he not just take it off instead of humiliating himself by visibly suffering in front of his minions? Angwë tried not to stare, or to make his discomfort too obvious.
"I give thee leave to speak," Morgoth said, "and thou shalt ask me two questions, and one boon shall be granted unto thee. Choose thou wisely and well, or thou might yet displease me."
"My Lord," Angwë faltered, unwilling to incur his new master's wrath, "I perceive that thou hast suffered great pains in the undertaking of thine efforts, for behold, thou hast sustained burns to thy forehead where the Silmarils rest upon it on thy crown. Thy hands are burned also and heal not. Wherefore dost thou remain in such torment?"
"Thou knowest well that I desired these jewels since Fëanor the Elvensmith first wrought them in Valinor," Morgoth replied, "but it seemeth that thou knowest not why. Is this thy true intent, to discover the meaning of my desire and the torment I must endure even as I wear the Silmarils upon my brow?"
"It is," Angwë confirmed.
"Then I shall tell thee," Morgoth replied. "Long have I desired to attain the power of the One Who wields the Secret Fire that giveth life to all things that live. This Secret Fire, or a part thereof I believe to have been caught up in some fashion in these jewels. I have not discovered how to break them, and I fear losing the power held within them if I should attempt this. I have seen that great fortune attendeth those who hold these jewels, but there is a great curse upon them also. The curse upon them is twofold: that laid first by Manwë forbids me or any of my servants to lay our hands upon them; the second is that the sons of Fëanor and all who took his Oath will pursue unto death or their own destruction any who should withhold the Silmarils from them. If I should relinquish them mine own work may well be undone, for they sustain those things that grow of the power of Eru, and these I need for the feeding of mine own creatures."
"My Lord, by your leave I will ask my next question," Angwë said, emboldened by the favour he had apparently just won. "My Lord, canst thou bring forth life on thine own, without aid from Eru?"
"Long have I sought to do so," Morgoth replied, "but I have been hindered by the fact that this is only enabled when I give of myself. It is meet that I should have this power, for I was the first of the Ainur, the strongest of the Valar, and I arose in might. However, Eru has kept unto Himself the ability to create life and sustain it without diminishing Himself in any way. He alloweth Aulë to bring forth his unlovely folk to tear down that which thou thyself hath built, and hath sanctified them that they might live and make their mark, yea, ever do they profit from thy works; yet I may not do likewise! Aulë was ever jealous of me, and ever sought to lift himself up in the eyes of the One while I was cast down. Therefore I brake the Great Lamps that he made, and brought Ungoliant to feast upon the Two Trees, that his light would be undone and his prestige diminished thereby. But behold, he and his helpers have brought forth new torments - these bright lights that burn, the Sun and Moon, and lo! He is not content, for he ever seeketh to undo what I have done, and will allow me no peace to build a realm of mine own."
The bitterness in Morgoth's voice found a haven in Angwë's heart, for Angwë knew what it was to be denied that which he desired for the sake of lesser beings. He spoke again, and this time it was to ask for the promised boon. "O Lord, may I ask thee now for the boon that thou hast promised me?"
"Thou mayest," Morgoth replied.
"Give unto me my mountain, Celebdil, that I built with mine own hands. Give me leave and the aid I need to drive out the Dwarves that infest it that I may have it as a realm of mine own. Promise me this and verily I will serve thee, and be a true vassal unto thee until the ending of the world," Angwë begged.
"I will do for thee as thou askest of me," Morgoth replied, "But first thou shalt do all I shall require of thee, and if thy heart should grow faint at the prospect of the commands I will give thee, then all is forfeit and all thy striving and thine efforts will have been in vain."
Morgoth got up and stood before Angwë. Stretching forth his hands, he placed them on either side of Angwë's head, forcing him to take the shape he desired him to have. Singing a song of great power, he cast a spell that wove a form around the shape. Fiery and dark it was, harnessing the latent power Angwë possessed, but turning it to his own advantage. By imprisoning Angwë in this shape he was able to control him more fully by giving him cause to fear personal harm, thus making him dependent on him for safety. Long was his labour, and when he was finished, he led Angwë to a small pond so he could view his own reflection. A great mountainous monster he saw, with powerful arms and cloven hooves where his feet once were. On his head were great horns, and from his back wings had sprouted. Morgoth spoke more words of power, and Angwë involuntarily flicked out his hand. A great many-thonged whip of fire appeared in it, and in his other there was a mighty sword. Angwë grinned and roared. He was a Balrog.
"Now have I given thee a part of what thou desirest," Morgoth said, "now shalt thou make payment in full ere I release thee to do thine own will."