Where is the place Gandalf tells the Witch-king to go?

Question

When Gandalf encounters the Witch-king during the battle at Minas Tirith, he tells the Witch-king:

'Go back to the abyss prepared for you! Go back! Fall into the nothingness that awaits you and your Master. Go!'

^{Return of the King Book V Chapter 4: "The Siege of Gondor"}

I was wondering if Gandalf was referring to the same place Morgoth is imprisoned in or somewhere else.

Here's an interesting paragraph from The Silmarillion, Valaquenta, "Of the Enemies":

Among those of his servants that have names the greatest was that spirit whom the Eldar called Sauron. In his beginning he was of the Maiar of Aulë, and he remained mighty in the lore of that people. In all the deeds of Melkor the Morgoth upon Arda, in his vast works and cunning, Sauron had a part, and was only less evil than his master in that for long he served another and not himself. But in after years he rose like a shadow of Morgoth and a ghost of his malice, and walked behind him on the same ruinous path down into the Void.

Answer 1

I find it unlikely that Gandalf is referring to the Void where Morgoth was sent after the War of Wrath; it seems doubtful to me that this would have been Sauron's fate, and the fate of the Witch-king (as a mortal) is unknown to us and Gandalf — declarative statements made from ignorance aren't his style.

Although no writings directly confirm this, I'm inclined to suggest that Gandalf isn't referring to any specific location, and is rather being poetical; a fancy way of saying that the Forces of Evil will lose the war, and Sauron and the Witch-king will be destroyed.

My interpretation is at least partially supported by a draft version of the line, which seems to more clearly imply that "the nothingness that awaits you and your Master" is merely the nothingness of death:

'You cannot pass,' said Gandalf. 'Go back to the black abyss prepared for you, and fall into nothingness that shall come upon your Master.'

^{History of Middle-earth VII The War of the Ring Part 3: "Minas Tirith" Chapter VI: "The Siege of Gondor"}

Answer 2

Yes, he was likely condemning the Witch-king to the Void. Most of the villains in The Lord of the Rings end up going there. As you say, The Silmarillion confirms that Sauron ended up in the Void:

"Sauron had a part, and was only less evil than his master in that for long he served another and not himself. But in after years he rose like a shadow of Morgoth and a ghost of his malice, and walked behind him on the same ruinous path down into the Void.”

(The Silmarillion)

This probably did occur with the intervention of the Valar:

'The realm of Sauron is ended!' said Gandalf. 'The Ring-bearer has fulfilled his Quest.' And as the Captains gazed south to the Land of Mordor, it seemed to them that, black against the pall of cloud, there rose a huge shape of shadow, impenetrable, lightning-crowned, filling all the sky. Enormous it reared above the world, and stretched out towards them a vast threatening hand, terrible but impotent: for even as it leaned over them, a great wind took it, and it was all blown away, and passed; and then a hush fell.

(The Return of the King)

Our hint is the "great wind" which is clearly meant to provide an association with Manwë.

Something very similar happened to Saruman:

To the dismay of those that stood by, about the body of Saruman a grey mist gathered, and rising slowly to a great height like smoke from a fire, as a pale shrouded figure it loomed over the Hill. For a moment it wavered, looking to the West; but out of the West came a cold wind, and it bent away, and with a sigh dissolved into nothing.

(The Return of the King)

Tom Bombadil sent the Barrow-wight to the Void:

Tom stooped, removed his hat, and came into the dark chamber, singing:

Get out, you old Wight! Vanish in the sunlight!
Shrivel like the cold mist, like the winds go wailing,
Out into the barren lands far beyond the mountains!
Come never here again! Leave your barrow empty!
Lost and forgotten be, darker than the darkness,
Where gates stand for ever shut, till the world is mended.

At these words there was a cry and part of the inner end of the chamber fell in with a crash. Then there was a long trailing shriek, fading away into an unguessable distance; and after that silence.

(The Fellowship of the Ring)

But this shouldn't surprise us. Most likely, all Men go to the Void. Even Gandalf did, in mortal form.

Then darkness took me, and I strayed out of thought and time, and I wandered far on roads that I will not tell.

(The Two Towers)

The Gift of Men is precisely that they are not bound to the world.

It is one with this gift of freedom that the children of Men dwell only a short space in the world alive, and are not bound to it, and depart soon whither the Elves know not

(The Silmarillion)

That said, there are other things in the Void besides just Void: the Halls of Ilúvatar are not a bad place.

Answer 3

Well, it is clear that Gandalf is connecting the fate of the Witch-king with that of Sauron. From the movie (the book's wording is similar):

GANDALF: (He holds his staff across the front of him.) Go back to the abyss! Fall into the nothingness that awaits you and your master!

Now, this answer explains what happened to Sauron: He existed a bodiless spirit, incapable of doing harm. Since Gandalf must have know that this would be Sauron's fate, it seems clear that the Witch-king is doomed to a similar state. Though the Witch-king was originally human, it is possible that his corruption has forced him to remain bound to Sauron even unto death.

Answer 4

I think that this question is more complicated than it looks and several of the answers -- while thoughtful and well-researched -- may be trying to make things too simple and to deduce the best procrustean bed.

We know that

Morgoth himself the Valar thrust through the Door of Night beyond the Walls of the World, into the Timeless Void;

It seems clear that this "Timeless void" is the same as the Void in which Arda was englobed when Iluvatar created it:

Iluvatar arose in splendour, and he went forth from the fair regions that he had made for the Ainur; and the Ainur followed him.

But when they were come into the Void, Iluvatar said to them 'Behold your Music!' And he showed to them a vision, giving to them sight where before was only hearing; arid they saw a new World made visible before them, and it was globed amid the Void, and it was sustained therein, but was not of it. And as they looked and wondered this World began to unfold its history, and it seemed to them that it lived and grew.

Melkor had gone down into Arda at the beginning at the same time as the Valar. After his final defeat, the Valar thrust him out in such a way that he could not re-enter. How? Tolkien does not tell us, but we can make a reasonable guess.

Throughout the Silmarillion and LotR the invariable consequence of a creature doing evil is a diminishment of that creature's own being, it's own self. Since a creature's strength and power and ability to act in the world is in large part determined by its strength of being, the practice of evil diminishes the creature. (Melkor lost fighting power -- once the greatest of the Ainur he finally found the Elf Fingolfin to be a tough opponent -- and eventually lost his ability to change his body or even to heal his own wounds.) It is likely that by the end Morgoth simply lacked the capability to re-enter Arda unbidden so whatever was left of him was stuck in the Void: Unable to re-enter Arda and unwilling to re-enter the Halls of Iluvatar.

Both Sauron and Saruman diminished themselves likewise:

[In Sauron's case, when the Ring went into the fire,] it seemed to them that, black against the pall of cloud, there rose a huge shape of shadow, impenetrable, lightning-crowned, filling all the sky. Enormous it reared above the world, and stretched out towards them a vast threatening hand, terrible but impotent: for even as it leaned over them, a great wind took it, and it was all blown away, and passed; and then a hush fell.

[When Wormtongue killed Saruman,] To the dismay of those that stood by, about the body of Saruman a grey mist gathered, and rising slowly to a great height like smoke from a fire, as a pale shrouded figure it loomed over the Hill. For a moment it wavered, looking to the West; but out of the West came a cold wind, and it bent away, and with a sigh dissolved into nothing.

This is the last we hear of either of them, but we also have Gandalf's prediction of what would happen to Sauron if the Ring is destroyed:

then he will fall; and his fall will be so low that none can foresee his arising ever again. For he will lose the best part of the strength that was native to him in his beginning, and all that was made or begun with that power will crumble, and he will be maimed for ever, becoming a mere spirit of malice that gnaws itself in the shadows, but cannot again grow or take shape. And so a great evil of this world will be removed.

Note that Gandalf -- surely an expert if anyone is -- sees Sauron (or what's left of him) remaining in Arda, but so diminished that he is of no consequence. This also fits Saruman's fate, as far as we know it: He dies, his stunted and diminished spirit rises (perceived by the Hobbits as smoke), and turn to the West from which a wind arises and disperses whatever is left into the air of Arda.

In neither case is there anything at all to suggest a thrusting out of Arda into the Void beyond.

The explanation, I think, is that Morgoth actually was thrust out of Arda into the Void beyond, but the remnants of Sauron and Saruman went into the void of nothingness. This is entirely consistant with Tolkien's religious understanding of evil: Evil does not exist as a thing, but only good, with the scale running from God on one end to nothingness on the other. Morgoth, Sauron and Saruman were created high in goodness and through their own actions, the latter two anyway, through their own choices made themselves less and less good to the point where, at their deaths, they had diminished themselves to close to nothing at all.

Morgoth's Void may be real (though never forget that we're dealing with Mannish legends derived from what Elves told them of what they remembered hearing from the Valar), but Sauron's void and Saruman's is the void of personal nothingness. And that is where Gandalf sees the Witch-King heading.