1. ‘Gaudrim’ is a Sindarin word (‘people of the machine’); so is ‘Caras Gaer’ where the wizard lives (‘sea-fortress I think). Somebody around here speaks Sindarin.

2. Horses have the same bits we’ve seen on elf-horses before (Galadriel’s horse in ep1 above, Gaudrim horse in ep2 below)

3. TROP Celeborn isn’t dead so he’s got to be somewhere remote and presumably trapped? amnesiac? something? ‘Kept in a prison camp by Sauron or Adar’ is an obvious one but other than Sauron clearly not being in a place to run prison camps - eating centipedes, failing to get job etc etc - being an orc prisoner for centuries would surely mess you up to the point where it would be hard to come back in as an active story participant like “well anyway, where were we?” and Rhûn is the most distant place we’ve seen so far that’s also disconnected from the main elves.

4. The Gaudrim have some ‘curse upon our flesh’ which, okay, is implied to be linked to why they wear their masks, but what if it’s more than that? what if ‘the machine’ is controlling them somehow? what if some or all of them are elves but don’t remember they are?

5. TROP Celeborn is linked to forests (they haven’t said ‘Doriath’ but it’s implied); they’re clearly doing SOMEthing with dead trees and desertified land; what better place to bring in an elf that’s into trees to the point of staying in Middle-earth for them?

6. and there’s some tree-like detail on Caras Gaer and Brank’s armour, plus a statue holding a palantír(?) outside Caras Gaer

7. it makes decent narrative sense to bring Celeborn in linked to another storyline and let him have his own direction as a character rather than parachute him in for Galadriel like “ta-da! husband’s back now” (boring) or create a whole new storyline for him (not enough space in season): therefore, Rhûn.

Collecting up my lost-Sindar-in-Rhûn speculation posts on where Rings of Power's Celeborn is, because there's a few now and we have maybe another 18 months to go at best before getting any answers on it.

My posts about this:

Written during s2 speculating he was one of the Gaudrim: one, two

Rhûn's desertified land and dead trees as deliberately paralleling Anfauglith as the opposite of Doriath

And a post on TROP's 'Rhûnic', possibly the language of a 'lost tribe' of elves

And Gandalf's mysterious past.

Fics I've written with this premise:

Lands far away (2000 words, G) - catching up with Gandalf many years later in Third Age Lothlórien

Five places Celeborn hasn't spent the past eight hundred years (7k words, T) - as the title says, five different alternative stories of which chapter 4 is the Gaudrim-in-Rhûn one

The names of our wounds (ongoing WIP, M, Galadriel/Sauron/Celeborn)

The thinking:

Celeborn has got to be somewhere at this point: the overall outline of this show has already been planned out with said plan okayed by the Tolkien estate who had a "no killing off any characters who don't canonically die yet" clause, and the show is slavishly determined to line up with the Peter Jackson films as a prequel. (This also probably means we'll get boring-coloured hair for him, alas.)

By TV convention, missing-presumed-dead spouses and loved ones who are mentioned in a tragic way in season 1 have a 65-80% chance of turning up alive, well and working for the bad guys by season 3. Say what you will about McPayne's former boss JJ Abrams but he had one of the best takes on this with Alias.

The show has too many plotlines as it is and has little space for a whole new 'Galadriel Looks For Her Missing Husband' one, plus taking Galadriel out of the War of the Elves and Sauron while that's actually happening would make no sense for her character & role. It makes more sense to introduce Celeborn as part of an existing plot, and Rhûn is the one that's most geographically and narratively separated from all the others.

Rhûn is currently the only place with a powerful magical villain who could potentially be keeping prisoners and certainly seems to be keeping some people under some sort of magical control - Brank, the Gaudrim character who got most of the lines, talked about the "curse upon our flesh".

Putting a prince of a forest kingdom (Amazon confirmed they're using the Doriath version of Celeborn) in a land of dead trees and giving him a storyline connected to whatever's happening there works a lot better for establishing a character than just "hey look Galadriel's missing husband who you don't know is back now!"

The show is doing a lot of things that if you want to see it that way already feel like they're setting up an elves-in-Rhûn story, including eg Sindarin names turning up for 'Caras Gaer' and 'Gaudrim'

I'm less confident on him being one of the Gaudrim we've met specifically than on him being in Rhûn generally, but if he is, he's 'Kilta' - the one who killed the snake that was about to strike Poppy and Nori, looked straight at their hiding place, and told the others to mount up and search elsewhere. (With thanks to @oroniel for noticing that 'kil' in Primitive Elvish had a meaning of 'silver glint', and 'ta' also could be 'high, lofty' - one of the translations JRRT gave for 'Celeborn' is 'Silver-tall')

And thanks to Peter Jackson's films the one thing the general audience know about Galadriel's husband is that he's the guy who very much wanted to speak with Gandalf (it's not his line in the book!), and this is the kind of show that will therefore want to give him a whole Surfing Dracula backstory on why he wanted to speak with Gandalf.

and I can think of one Sindarin elf who in Rings of Power continuity might currently be hanging around ‘deeper in Middle-earth’ in a plotline that will overlap with Gandalf’s…

(had to add that, sorry! I'd probably have dropped this by now, but people got deeply weird about Celeborn theorising to the point of muttering about "motives" and saying "people need to STOP posting Celeborn 'theories'!", so now I am afraid I must do it solidly for the next 43 years. There are not many fandom hills worth dying on but "you do not get to order other people around on how to have fun with made-up elves" is very much one of mine!)

How will Fae and Bòr’s story end?

Will Fae’s silence cost her? What of the grimoire? And, Bòr’s true intentions?