Thanks to Everleigh for correcting a few critical points! It's my birthday, so in the best hobbit tradition, here is a mathom to anyone reading this. :)

Gorthaur is the Sindarin name for Sauron

Imladris SA 3434 (before the Last Alliance of Men and Elves)

He found Elendil standing on one of the plateaus, looking out across the valley floor, every bit of landscape flat enough to raise a tent occupied by either men or Gil-galad's army.

"Will it be enough?"

"Lórien and Greenwood will join us." Elrond did not voice his concerns that maybe they would not. The Silvan and Sindarin Elves had no great love for the Noldor, and had already voiced protests at marching under Gil-galad's banner. He had faith that Celeborn would persuade them to join the fight, for they hated Gorthaur.

"Even then, Elrond." Elendil shook his head, gaze distant, past the high cliffs, maybe seeking south to where Anárion dwelt in Osgiliath. A sigh and he turned to face his friend. "There is some light in this present darkness that I would share with you."

"Please."

Grey eyes alight with delight, Elendil smiled. "My son's wife is with child."

Hiding his surprise, this was an ill time to bring forth children, with war at their doorstep, Elrond paused as something quiet in him whispered that great good would come from this. He smiled and gripped Elendil's forearm. "May this babe grow in strength and wisdom, and find long days in peace."

"I dearly hope so." Patting Elrond's hand, he released him and looked again out at the valley. "Will it be enough? Can you foresee any future?"

"It is dark now," Elrond said, cautious of offering false hope. What he could see was murky, fraught with sadness and loss, but... Far off, so distant that it seemed but a wisp of vapor, Elrond had the merest glimpse of hope. He would come from this man, from his sons and their sons, many generations away, from Elrond's own brother, Elros.

Nothing was certain.

But he met Elendil's gaze and spoke strong and sure. "I see hope, yes. Far off yet, and the way is not clear, but I will cling to that and do all I am able to see it brought forth."

"I can ask for nothing more." Elendil sighed and it seemed a great weight fell from him. "We will bind this Alliance of Men and Elves with an oath, and ask Eru, who is above all thrones forever, to bless it." He nodded and smiled. "I will hold to hope, and fight with all the strength that is in me."

Minis Tirith, Beginning of the Fourth Age, 39 generations later

Elrond watched as Estel...Aragorn II, Chieftain of the Dúnedain, stood before the crowds gathered and took the crown from Faramir, and held it up to say, "Et Eärello Endorenna utúlien. Sinome maruvan ar Hildinyar tenn' Ambar-metta" ("Out of the Great Sea to Middle-earth I am come. In this place will I abide, and my heirs, unto the ending of the world"), the very words Elendil had spoken upon surviving the great wave that had drowned Númenor.

Time waivered for a moment, the world falling away as Aragorn gave the crown back to Faramir and spoke to him, asking him to give it to Frodo, who bore it to Gandalf. As if from a distance, Elrond saw Aragorn kneel and Gandalf set the White Crown upon his head, and said: "Now come the days of the King, and may they be blessed while the thrones of the Valar endure!"

Elrond saw Elendil, smiling at him that morning, telling him of a child to come. "Your hope has arrived, my friend," Elrond murmured. "May his days be blessed."

"Behold the King!"

Notes:

This is a mix of movie and book (filched unashamedly from Return of the King) - Elrond didn't come into the Minas Tirith until Midsummer's Day, when he brought Arwen and the scepter of Annuminas to Aragorn, but for this story's purpose... I wanted him to see his foster son, his Estel, his hope so long ago foretold, crowned.
Thank you for reading! I hope you are finding peace and comfort in this truly weird time we're living through. Don't give up hope, and when you have it, share it with someone else. We will get through this together.