It takes as long as the spring only because they weren't looking. They can stretch the oath that far, they can be disinterested in knowing - but now they know, and so there it is. Elwing of Sirion is twenty-three. Half-man, so fully grown. Sirion is a city of refugees. Elves and Men and, since there are Men, children. Elwing herself has infant children.
They debate whether to send messengers. Debating is allowed, even protracted debating. The Oath, these days, is loud in their minds, and louder when they're pushing it like this, but they drag out the debate for a few months. Messengers will probably be shot on sight. The last time Elwing of Sirion received news of the House of Fëanor it would have been the news that her brothers, twins, aged seven, had not survived the sack of Menegroth.
They send messengers anyway. The messengers are shot on sight. They have good armor, Fëanorian armor, and return home injured but not lethally. Maglor's songs no longer stitch them together. War makes you worse at healing. Maglor's songs are more powerful than ever - he can knock back a wave of approaching enemies, he can make a blade's next touch deadly, he can make them faster and more impervious to danger, but he can no longer do healing.
Maedhros, when he thinks about this, thinks that perhaps there needs to be part of you that is not broken for healing spells to draw on. Or perhaps the Enemy is amused to strip that away first. Perhaps the Enemy finds it suited to the theme as the Oath tugs and yanks and twists them into violence against the lands they once defended and the peoples they once sheltered.
They send messengers to Sirion again. The messengers deliver a plea for the Silmaril, an offer of anything at all in exchange. The messengers do not return at all.
The Enemy is many many hundreds of miles from here but at night Maedhros can hear him in his head. Is it so implausible that I really let you go? the Enemy likes saying. You serve me better free than you ever would have willingly.
The Oath allows them to work slowly. They begin planning the sack of the refugee camp even more slowly than the Oath allows, so slowly that its currents are constantly tugging at them. Any slower and the currents would erode all the things they care about which are not the Oath, and it would be a disaster to go to Sirion once they've been stripped of their capacity to care about anything that is not the Silmaril. So they do not hold out forever. But they work as slowly as they can.
Are there going to be weird time travel problems depending on how I release you? Also I would like to know what you're going to do to fairy orders so I know what to expect.
I will not edit anything that you experience as earlier than this moment in the timeline. The Eldar will all become like Maedhros immune to fairy orders and unable to vassalize fairies. So will I; so will the Valar; the Dwarves might already be because of their immunity to mind-effecting magic but if not, they will as well. I don't think I will make fairy orders impossible on all of the worlds, because then you won't be able to go do interesting things and tell amazing stories there.
Okay. I will go ask at a temple if I think of something. Deep breath. You may operate freely.
"I let him go," she says. "Fairy orders aren't going to work on Elves or Valar or Maiar or Dwarves anymore."
"Oh, and they don't work on him either now. He left them on the other species. ...Possibly expressly to allow me to operate with my customary set of abilities because he thinks I'll create interesting stories."
"I think it should be doable," Curufin says, "orders have to be parsed as language -"
"But fairies do really bizarre language parsing to start with -"
While they continue this conversation Maedhros smiles at her, looking almost relaxed. Well done.
Promise sings, where that will help. Is Fëanor too busy with the city to pay attention to sorcery notes yet?
He is not! He has read through them and has two possible avenues to gates: one is to make a magic artifact that stabilizes harmonics locally so they can gate, and the other is to find a non-sorcerous means of gating. The latter will probably go a little faster but the former might be more useful, what does she think?
The former would indeed be more useful! Although the planet with the star shaped continent is going to have nice harmonics anyway.
She misses her tree. But it would take a really long time to grow one here big enough to live in without sorcery anyway. Also Thorn might have the place staked out and could take a while to stop doing that. She can wait.