The Silmarillion

It chanced that Celegorm and Curufin went on a hunt through the Guarded Plain; and this they did because Sauron, being filled with suspicion, sent forth many wolves into the Elf-lands. Therefore they took their hounds and rode forth; and they thought that ere they returned they might also hear tidings concerning King Felagund. Now the chief of the wolf hounds that followed Celegorm was named Huan. He was not born in Middle-earth, but came from the Blessed Realm; for Oromë had given him to Celegorm long ago in Valinor, and there he had followed the horn of his master, before evil came. Huan followed Celegorm into exile, and was faithful; and thus he too came under the doom of woe set upon the Noldor, and it was decreed that he should meet death, but not until he encountered the mightiest wolf that would ever walk the world.

Huan it was that found Lúthien flying like a shadow surprised by the daylight under the trees, when Celegorm and Curufin rested a while near to the western eaves of Doriath; for nothing could escape the sight and scent of Huan, nor could any enchantment stay him, and he slept not, neither by night nor day. He brought her to Celegorm, and Lúthien, learning that he was a prince of the Noldor and a foe of Morgoth, was glad; and she declared herself, casting aside her cloak. So great was her sudden beauty revealed beneath the sun that Celegorm became enamoured of her; but he spoke her fair, and promised that she would find help in her need, if she returned with him now to Nargothrond. By no sign did he reveal that he knew already of Beren and the quest, of which she told, nor that it was a matter which touched him near.

Thus they broke off the hunt and returned to Nargothrond, and Lúthien was betrayed; for they held her fast, and took away her cloak, and she was not permitted to pass the gates or to speak with any save the brothers, Celegorm and Curufin. For now, believing that Beren and Felagund were prisoners beyond hope of aid, they purposed to let the King perish, and to keep Lúthien, and force Thingol to give her the mightiest of princes of the Noldor. And they did not purpose to seek the Silmarils by craft or war, or to suffer any others to do so, until they had all the might of the Elf-kingdoms under their hands. Orodreth had no power to withstand them, for they swayed the hearts of the people of Nargothrond; and Celegorm sent messengers to Thingol urging his suit.

But Huan the hound was true of heart, and the love of Lúthien had fallen upon him in the first hour of their meeting; and he grieved at her captivity. Therefore he came often to her chamber; and at night he lay before her door, for he felt that evil had come to Nargothrond. Lúthien spoke often to Huan in her loneliness, telling of Beren, who was the friend of all birds and beasts that did not serve Morgoth; ad Huan understood all that was said. For he comprehended the speech of all things with voice; but it was permitted to him thrice only ere his death to speak with words.

Now Huan devised a plan for the aid of Lúthien; and coming at a time of night he brought her cloak, and for the first time he spoke, giving her counsel. Then he led her by secret ways out of Nargothrond, and they fled north together; and he humbled his pride and suffered her to ride upon him in the fashion of a steed, even as the Orcs did at times upon great wolves. Thus they made great speed, for Huan was swift and tireless.

In the pits of Sauron Beren and Felagund lay, and all their companions were now dead; but Sauron purposed to keep Felagund to the last, for he perceived that he was a Noldo of great might and wisdom, and he deemed that in him lay the secret of their errand. But when the wolf came for Beren, Felagund put forth all his power, and burst his bonds; and he wrestled with the werewolf, and slew it with his hands and teeth; yet he himself was wounded to the death. Then he spoke to Beren, saying: 'I go now to my long rest in the timeless halls beyond the seas and the Mountains of Aman. It will be long ere I am seen among the Noldor again; and it may be that we shall not meet a second time in death or life, for the fates of our kindreds are apart. Farewell!' He died then in the dark, in Tol-in-Gaurhoth, whose great tower he himself had built. Thus King Finrod Felagund, fairest and most beloved of the house of Finwë, redeemed his oath; but Beren mourned beside him in despair.

In that hour Lúthien came, and standing upon the bridge that led to Sauron's isle she sang a song that no walls of stone could hinder. Beren heard, and he thought that he dreamed; for the stars shone above him, and in the trees nightingales were singing. And in answer he sang a song of challenge that he had made in praise of the Seven Stars, the Sickle of the Valar that Varda hung above the North as a sign for the fall of Morgoth. Then all strength left him and he fell down into darkness.