Warning: spoilers ahead for The Rings of Power episodes 1 & 2Did The Lord of the Rings: The Rings of Power just reveal the story behind Moria's Doors of Durin? The Fellowship of the Ring had just as much trouble getting into Khazad-dûm as they did getting back out, and that's partly thanks to the Doors of Durin. This west gate takes the form of an ornate glowing door carved directly into the mountain with no obvious opening, handle or doorbell. Only the riddle "speak friend and enter" offers any clue for getting in, and the answer somehow eludes four hobbits, two men, an elf, a dwarf, and a wizard far longer than it should.
In The Rings of Power, the abandoned dwarf mine is a thriving kingdom known as Khazad-dûm, ruled by Durin III. His son (and Moria's prince) Durin IV is a longstanding friend of Elrond's, so when Celebrimbor demands a team of skilled craftsmen and construction experts for an ambitious new project, Robert Aramayo's character knows exactly where to go. The two elves make the short journey from Eregion to Khazad-dûm to deliver their proposal, but The Rings of Power's Moria entrance is wildly different compared to The Lord of the Rings. There's no glow and no magic - just good, solid rock and a heavy-duty opening mechanism with a gruff guard telling would-be guests how best they can go away.
As written in J.R.R. Tolkien's The Lord of the Rings appendices, the Door of Durin was built when the dwarves of Khazad-dûm began friendly relations with the elves of Eregion. The door was a joint project between Celebrimbor and the dwarf Narvi, hence the presence of elven writing and magical properties that Khazad-dûm's entrance lacks in The Rings of Power episode 2. Elrond and Celebrimbor visiting Moria (the latter seemingly for the first time) neatly sets up how and why the Doors of Durin are built. Celebrimbor has seen Khazad-dûm's current door situation in person, and knows they'll need something more efficient if cooperation is to happen. Celebrimbor may even offer to improve their entryway in exchange for building his big forge. In The Rings of Power episode 2's final moments, Durin III then brings out a box with a mysterious glowing mineral inside. This is most likely mithril, which sets up the Door of Durin's glowing silver inlay. In these few scenes, The Rings of Power shows how the Door of Durin collaboration began, how the entrance was improved, and why it was so important to the Dwarves' rocky relationship with Elves.
The Rings Of Power Makes LOTR's "Friend" Riddle More Important
Khazad-dûm's "speak friend and enter" riddle has always been symbolic of the friendship between Moria's dwarf-kingdom and Eregion, but The Rings of Power makes that connection far more personal. Eregion and Khazad-dûm apparently aren't yet in cahoots when The Rings of Power begins, and the foundation of their alliance is actually Elrond and Durin IV, who met 50 years prior in some unknown circumstance. Durin is hurt because Elrond hasn't swung by for two whole decades, so when the elf claims to be a friend at Khazad-dûm's entrance, he's not permitted to enter. The old pals heal their wounds over dinner with Disa, Durin's wife, and this reconciliation paves the way for a working relationship between their respective races.
It's poetic that once the Doors of Durin are built and the bond between settlements is cemented in The Rings of Power, the very entrance Elrond was turned away from upon claiming to be Durin IV's friend in episode 2 will be enchanted so that he needs only say the word "friend" in an elven tongue, and access shall be granted. It's a poignant addition to Moria's mythology, and means Elrond has no excuse to wait 20 years between visits to his bearded friend.
The Lord of the Rings: The Rings of Power continues Thursday/Friday on Prime Video.