Vimes, Vetinari and the Discworld belong to Pratchett. Middle Earth and everything in it is Tolkien's.
"I see", said Lord Vetinari, his voice carefully controlled. "In that case, we will make… other arrangements."
"Oh, you know." Vetinari seemed absorbed in his paperwork, and did no more than wave a long hand vaguely. "Alternatives."
Commander Vimes of the City Watch saluted precisely. He was suspicious. He was suspicious before the interview had started, and he was suspicious now. Suspicion was an integral part of Vimes' genetic makeup in any case, but Vetinari's casualness was not helping. Someone had once described Suspicion as a spiky little imp. If that was the case, Vimes reasoned (1), Vetinari's casual air had just given it caffeine.
"Yes. If you don't want to be our fair city's ambassador to Middle Earth," said Vetinari, "- emphasising, of course, that the position is entirely voluntary- then we will just have to find someone else."
Vimes was fascinated. Vetinari's lips had pronounced 'our fair city' with barely a quirk of distaste at the monstrous dishonesty of the phrase.
"Indeed. And please stop repeating my words" He sent Vimes a cool glance over the top of his paperwork, and continued. "In fact, I think that would be preferable. You are, as the Lady Sybil reminded me only this morning, a Duke. To send a Duke on a common ambassadorship is somewhat inappropriate. The role, I believe, involves running and sweatiness and the odd bit of mud. It is not, shall we say, very Ducal. And it is vitally important for Ankh-Morpork that the outcome we desire is achieved."
"Sir-" Vimes began. Vetinari waved a long hand.
"You're about to ask where the money is, aren't you? Your cynicism never fails to astound me."
"It is quite simple. Middle Earth is a backwards collection of lands, ruled by autocratic royalists and peopled by creatures to whom it would be a stretch to apply the word 'multicultural'. It is an unpleasant place. It keeps getting involved in nasty and pointless wars, and it is on the brink of another, particularly nasty, one. They have some frankly archaic notions of good and evil and allow these notions to influence major policy decisions."
Vetinari sighed, just barely. "It is also one of Ankh-Morpork's major trading partners."
"Ah." Vimes said. "I see". He saw. "And you want me to waltz in and do what, exactly? Ambassadorise? "
"Oh, no. No. You told me quite clearly that you are not interested."
Vimes saluted again. He was beginning to get the impression that he had lost.
"We will have to send someone else, instead. Do you have any suggestions?"
"I was thinking about sending young Carrot. He is doing very well, I believe. And there is a rather interesting situation that I believe Carrot might learn from."
"You see, my contact there is sending some of his men on some sort of- " Vetinari glanced at the papers. They were covered in squiggly rune-like letters that Vimes could not read, though he was squinting in a rather pronounced way in his attempt to. "- well, he uses the word 'quest'". Vetinari continued, looking faintly worried. "Oh dear.'
It worried Vimes, too. Anyone who would use the word 'quest' in a serious sentence must be some kind of Lord Rust type. And Vetinari considered the man his equal, so he must have significant power. That meant that some of the people in charge of Middle Earth were the sort that Vimes would happily arrest on a charge of being Naughtily Patriotic and wouldn't trust with the care of a small beetle.
"Your opinion on this, Captain?"
"Sir. The man sounds insane."
"Even more worryingly, Captain, he is not insane. That is simply how things work there. And he is not a man, exactly."
Vimes observed that they must have progressive ideas about gender in Middle Earth.
"Oh no, Captain. You misunderstand. He is, in fact, an elf."
"What, one of those skinny types with the high-pitched laughter? I really don't-"
"A real elf, Vimes. And in a position of great power."
Vimes sputtered. "But - why are we dealing with such people? Everyone knows elves stick sharp things into people for fun! What the hell are they thinking, putting one of those things in charge? The place must be bonkers!"
Vimes became aware of a chilly silence emanating from the Patrician. His voicebox, being a cowardly sort, elected to join in.
"Middle Earth has vast reserves of precious metals and minerals that we need. It is similar in many ways to our own world. Narrativatum plays a significant role there, as it does here. And they have gold. And silver. And something called 'mithril'. And, I believe, some of the finest treacle lakes in existence. They haven't even heard of natural treacle, and they sell us the stuff cheap. They don't even realise that you can get treacle out of the ground! Their dwarves are even better craftsman than ours. And by God, we need that treacle."
"You see my problem, Vimes. We must deal with this messed up, regressive country. And in order to do so, we must get... involved. They have internal problems at the moment with which we can help. If we do not do so, the people who might take power next will be even more difficult to deal with."
"Even than treacle?" Vimes cut in, rather suicidally. But Vetinari barely paused to glare at him.
"More importantly, the wizards inform me - with rather too much glee, it must be said- that Middle Earth is in danger of becoming dangerously imbalanced. If their Dark Lord wins, well, it would seriously disturb the narrativium deposits. The Dark Lord isn't meant to win. If he wins, the narrativium deposits are in danger of running out…"
"Don't you mean that the other way around?"
"Well, of course it could work the other way around, too. If Middle Earth was running low on narrativium, the Dark Lord would be more likely to win. However, if the Dark Lord wins, that would also affect the narrativium. Narrativium couldn't exist in a world where a Dark Lord wins. Even aside from trade, our world is similar enough to Middle Earth that we risk being dangerously imbalanced by such an event there."
"But in some ways, Middle Earth is remarkably different from the Discworld. There are elves there, Vimes. Elves that do more than giggle and hurt things. They actually appear to wield considerable political power without, as far as I can make out, smashing anything for fun."
Vimes felt surprise and disbelief at this, and so saluted.
"What does he mean by 'quest'?"
"Exactly that, I am afraid. He seems to have decided that the way to deal with this complex political conflict is to arm a "ragtag bag of adventurers" and send them to destroy the 'one ring'- I believe this to be a code word for a weapon of great power- in something he calls "the fires of Mt Doom."
This gets worse and worse, thought Vimes, wishing he could roll a smoke.
"To do this, he is sending an elf, a dwarf, the son of the kingdom which stands to gain most if the weapon falls into his hands, four small people whose role he does not fully explain, a wizard, and a long lost heir to the throne of the aforementioned kingdom."
'You can see why I think this little enterprise needs some sensible outside help."
Vimes counted slowly on his fingers. "You mean- he's sending a dwarf, and everyone knows they're greedy little buggers who covet treasure (though I know some fine, decent dwarves myself) with a powerful weapon that is probably gold, possibly jewellery?"
"And a wizard? Is he anything like our wizards?"
"One can only hope not."
"Four little people? They're not Nac Mac Feegle by any chance? Good grief, those things are powerful weapons in themselves. The last Nac Mac Feegle I met headbutted Detritus!"
"He calls them 'Hobbits'. Perhaps they are a regional variation."
Vimes continued making his way down his mental checklist. He was going from infuriating to most infuriating. "And an elf?"
"I am afraid I cannot comment on that. I can only assume their elves are slightly different from the ones that plague us from time to time."
"And a king."
"Technically, an heir."
"I hate long lost heirs. Swanking around, thinking they can just swan in and take other the bloody city just because they share some genes with some inbred old dead guy and have some sparkly jewellery and a broken sword they pulled out of a lake-"
"The sparkly jewellery is the Ring of Barahir, and the sword was not in a lake, but you are broadly correct."
"I hate royalty. I really hate them."
"You don't have to go," Vetinari said, as Vimes clenched and unclenched his fists. "As I said, I could send someone else".
"I was thinking Lord Rust..."
They both considered, briefly, sending Lord Rust to a place where even the people in charge used the word 'quest' as if they took it seriously.
"Or Captain Carrot?"
They considered Captain Carrot. He'd be perfect. He'd love it there. He'd inspire people, and make glorious speeches, and generally make himself useful. Questing, and honour... Carrot would fit right in.
"No. I'm not having him running around with long-lost heirs and enchanted jewelery. He's a growing lad, our Carrot. He doesn't need to be distracted by strange ideas".
Vetinari had won. Vimes was going to Middle Earth.
(1) after making a mental note to arrest whoever had come up with the metaphor