In The Book of Lost Tales Part 1 it tells how Manwë led Tulkas, Aulë, and Oromë to seek peace with Melkor in Utumno. This is my interpretation of that scene.

The great Lords of the Valar were clad all in raiment of war, and Manwë carried a large bow and a quiver of white arrows, and his armor was all in blue, and Oromë clad in brown with a long spear that rose above even the head of Tulkas, who wore naught but a simple tunic and an iron gauntlet upon his right hand, and Aulë was late from his smithy, and had with him only a hammer snatched from his smithy in a hurry.

The chain Angaino forged of seven metals of tilkil was carried by Tulkas and it was wrapped around his arms and back, yet only Melko would be bound by those links. And as they went to the fortress of Melko, that which was named Utumna, the lesser lords of Valinor accompanied them. Fionwë there was, and Nornorë herald of Manwë, and Telimektar son of Tulkas. Salmar and Ómar followed behind while the Fánturi rode on a cart as dark as jet and it was pulled by a raven horse and one of dappled grey.

And when that great procession came to the shores of the Shadowy Seas Ossë, vassal of Ulmo met them, and drew them across the ocean on a great raft. And Ossë was clad in shining mail, but Ulmo who was Lord of the Waters was far ahead, on the shores of Endórë.

So the gods crossed the Sundering Seas and came of the wide lands of Endórë and passed to the Mountains of Iron in a fury. And beyond those dark towers was a realm of ice, with frozen rivers and mountains. And some among the host quailed but Manwë remained determined.

And the host passed unfettered, and then some were heartened, but soon the hope came to an end.

And there in the darkest north came they to the fortress of Utumna, beyond even the broken pillar of Ringil. But they passed not into the fortress, for Melko shook the earth under them, and snow-capped peaks belched forth flame, and yet for all their array, Melko's servants had availed him naught.

And angered Tulkas smote the great doors of Utumna, and they shook but remained closed. Then Oromë swift as a deer raised his great horn and blew such a blast that the doors flew open and hung thereafter broken. Then Manwë raised his great voice and bade Melko come forth.

Melko heard them and sent forth his servant Langon, and he said: "Behold, he was rejoiced to see the gods before his gates. He would let them in save for the poverty of his abode which is not fit to entertain but two of your great number. He wishes that it not be Manwë of Tulkas for the one merited and the other demands richness and comfort of the greatest."

Then Ulmo and Manwë were wroth, and Tulkas would have strode forward had not Aulë restrained him saying: "Is not Melko only assailable by his pride?" And so the gods devised a plan to catch Melko with his own pride, and down went Nornorë who spoke these words: "Behold! The gods have come to ask the pardon of Melko, for seeing his anger and the world is rent beneath him, and they have asked why he is angry. Is he not the greatest among us and yet where is he in Valinor, then surety he has cause for indignation. The gods have come to Utumna and wish that thou would comest and dwell in Valinor in the halls of Makar until thy own home towed above the white peaks of Taniquetil! For thou Melko are the mightiest among them! They desire thy presence to compete their joy."

And hearing this Melko's pride surged forward and overwhelmed his cunning and he proclaimed: "At last do the Valar talk sweetly. But first I must have retribution for old affronts. Tell your lords to come down and do homage to me, save Tulkas only, for him I desire naught to see!"

Then Nornorë hastened from the presence of Melko and returned to the Valar. Tulkas smote his hands, wroth but Manwë said that they would do Melko's bidding, but for Tulkas to keep Angaino of seven metals. "For yet we may have need of it."

And so they left their weapons at the door and came to Melko upon his chair, and Manwë said: "Lo! We salute you in thine own hall!"

But Melko would not give up his game easily, and he said: "Nay! Come before me, Manwë, and kneel, and all of thou Valar, and then Tulkas shall come and kiss my feet." And then Manwë despite great wroth in his heart went forward and cast his gaze to his feet and knelt.

Now such wrath was felt by the Valar at that scene that Tulkas leapt forward despite Angaino, and Aulë and Oromë were behind him, and the hall filled with tumult. Melko shouted in a loud voice, and swung a black mace at Manwë, but there was a gust of wind and the weapon was torn away from Melko's grasp, and Tulkas smote Melko on the teeth, and Aulë bound him thrity times with Angaino, and Oromë said: "Would that he might be slain!" And Manwë replied, "Nay, for not yet may the gods die." And then Melko was borne away by Tulkas and Aulë, while Ulmo and Oromë brought to ruin the evil fortress of Utumna, and Manwë sentenced Melko to three Ages' imprisonment until he had a chance for parole and all the time he remained bound by Angaino.

And Utumna was razed and never again rose, and the Valar captured the most foul of Melko's servants, but Langon and Thû the wizard they found naught, and Thû would rise to follow Melko to destruction.