Warning: This article contains spoilers for “The Rings of Power” Season 2 Episode 5. Proceed with caution, friend!

The Doors of Durin are a famous part of “The Lord of the Rings” story. When the Fellowship of the Ring arrives on the spot, fleeing from wargs and orcs, they find the doors shut. Gandalf (in the books) and Frodo (in the movie) eventually discover the secret password of the Dwarven entrance — Mellon, the elvish word for friend. In “The Fellowship of the Ring” book, Gandalf laughs after they open, saying that the too-clever-by-half verbal key is “too simple for a learned lore-master in these suspicious days. Those were happier times.” 

While it’s a true statement, and one that we’ll talk about in greater detail in a minute, it’s worth noting that the simplicity of the password for the Doors of Durin belies the powerful capabilities of the magical entrance. In reality, the Doors of Durin are virtually impenetrable. They’re also easy to hide except in specific circumstances. In short, they provide a clever and extremely effective protection for the westward entrance into Khazad-dûm.

Gandalf actually says as much when they initially find the doors. In the book, the Wizard explains, “These doors open outwards. From the inside you may thrust them open with your hands. From the outside nothing will move them save the spell of command. They cannot be forced inwards.” So, while the Doors of Durin are a fun and light-hearted piece of Middle-earth lore, they are also a powerful protection against outside forces. The magically reinforced aperture is designed to be even stronger than the rock that surrounds it when closed. How? Unfortunately, we don’t know. As is his way with most magic in his world, Tolkien doesn’t overly explain the magic at work. But he does give us some information in another area: The door’s invisibility feature.

Before Gandalf talks about the impenetrability of the Doors of Durin, Gimli also addresses the secret nature of the doors, saying, “Dwarf-doors are not made to be seen when shut. […] They are invisible, and their own makers cannot find them or open them, if their secret is forgotten.” The key to finding the Doors of Durin is to come when the moon is shining, or it’s a really clear, starry night. This is because the doors are made with Ithildin, a special substance made from mithril that only reflects starlight and moonlight.

“The Hobbit” book has a similar encounter with hidden writing when Elrond finds “moon-letters” on the map of the Lonely Mountain. In that case, all that is cryptically clarified is that they are simple runes with the exception, Elrond says, “They can only be seen when the moon shines behind them, and what is more, with the more cunning sort it must be a moon of the same shape and season as the day when they were written.” The loremaster adds, “The dwarves invented them and wrote them with silver pens.” In that case, this is all the explanation we get, but likely, we’re looking at a second manifestation of Ithildin or something very similar.

The Doors of Durin are also a rare opportunity for Amazon Prime Video’s “The Rings of Power” series to bridge a link between the “Lord of the Rings” and its Second Age story set thousands of years beforehand. In Episode 2 of Season 2 of the series, Celebrimbor (Charles Edwards) invents Ithildin, although he doesn’t immediately use it on anything of note. It isn’t until the more recent Episode 5 that we see it used on the completed (and yet to be installed) Doors of Durin. Celebrimbor allows Narvi (Kevin Eldon) to reveal the doors, at which point the Dwarven master craftsman says, “Behold! The Doors of Durin. The new West-gate of our mountain. Unbreachable, visible only by moonlight, and guarded by a password known only to friends.”

Do you see that? The single line manages to include all of the biggest talking points about the doors. They are unbreachable due to their magical strength. They are visible only by moonlight because of the mithril-made Ithildin used to write on them. They are guarded by a password known to “friends” who need only speak the password (Mellon) to enter. It’s all there for those with the eyes to see.

The Doors of Durin are a fun piece of deep-cut lore, and on “The Rings of Power,” they represent a much-needed upgrade for the Dwarven entrance to their subterranean enclave. But the scene also hints at an even bigger element of the Doors — arguably one more important than their strength or secrecy. The “friend” element of the Doors of Durin isn’t merely a fun play on words or a passing addition. Tolkien used these doors as a key symbol of the unique friendship that develops between the Dwarves of Khazad-dûm and the nearby Elven smiths of Eregion.

This wild Elvish and Dwarvish alliance is nowhere more obvious than with the leaders of these artisanal groups: Narvi and Celebrimbor. This is briefly but directly outlined in the book “Unfinished Tales,” where Narvi is described as a “close friend of Celebrimbor of Eregion.” The book adds that “Celebrimbor had ‘an almost ‘dwarvish’ obsession with crafts’ […] entering into a close relationship with the Dwarves of Khazad-dûm, among whom his greatest friend was Narvi.” This is the real deal, guys. It’s the Legolas and Gimli-level inter-racial bromance of Middle-earth’s Second Age, and it is a critical link that shows the two races can overcome deep-seated antipathy and work together toward common goals (which most would agree is a critical message in these fractured times).

The Doors of Durin reveal scene in Episode 5 plays on this dynamic. Before Narvi unveils the doors, Celebrimbor introduces him by saying, “Dwarves and Elves working together. It was said to be impossible. But our cooperation has achieved this wonder. And today, we embark upon a new dream. To enshrine our friendship in stone.” After the reveal, Celebrimbor playfully adds, “Now take note, smiths. Watch Narvi very closely while he’s here, not only because he’s a masterful artist. He’s also a notorious thief. Do not let any jewels go missing.” A smiling Narvi responds, “Aye, well, try checking his pockets,” after which Celebrimbor tells the amicable group, “To a lasting friendship between Elves and Dwarves.” 

The Doors of Durin may be impeccably secret and impossibly strong, but it is the fact that they are an enduring symbol of the potential friendship between Elves and Dwarves that is their greatest and truest power.