"That's a Valinorean ship. Where'd you get it?—also which 'other one', one is not on this planet and the other is inside the planet and I don't think either is particularly accessible."

"I got the ship in Valinor, obviously. Didn't you come from there also—who are you anyway? And apparently the planet barfed it out again and some dwarves found it."

"My name is Canafinwë Macalaurë, called Maglor, second born and last surviving son of Fëanor, and I came from Valinor about fifteen and a half thousand years ago and have not been back since. I was not aware that was what was in Erebor, although it makes sense and I was probably trying very hard not to think about it."

"That's—a long time."

"Yes."

They go up to the ship and fly to Sokovia. They see the Quinjet parked on a flat spot high up on the Lonely Mountain, and land next to it.

"The mountain's definitely got some void spaces inside it if these scans are anything to go by. This seems to be the place where the rock is the thinnest. This here—" he points to a small hole in the rock—"we think might have been a keyhole once but it's unlikely the door would still be operational even if we had a key."

"There was a key, once. I don't know what became of it. Erebor's been deserted for thousands of years."

"Right. Time for plan B, then—stand back, everybody—"

He throws Stormbreaker at the door, which smashes a hole large enough to climb through.

They go through the hole. The passageway beyond is about five feet high—clearly not built for people of human, never mind Elvish, stature—but at the end it opens onto a vast cavern, high above the ruins of an ancient underground city. A narrow stair descends the cavern walls. They go down.

Below the city, down another stair, lies the crypt of the kings, a long row of tombs decorated with statues of squat and bearded figures, their stone faces proud and grim, their hands folded atop great stone axes. The tombs have inscriptions in an unknown runic alphabet.

"I can read the inscriptions but I don't in fact know the name of the king we're looking for—he was called Thorin among the other races of Arda, but the Dwarves kept secret names in their sacred tongue, which they rarely told to any of another race. I suppose I could go by date of death—" He walks along the row, reading the dates of death.

"Here. 23rd Hithui 2941—of the Third Age, it's now the Sixth," he adds. "That's, let me see, 6537 BC by your calendar."

"Are we sure about this? I wouldn't normally believe in curses on ancient tombs, but I'm standing between an elf and a Norse god so I'm not actually so sure."

"The object inside is cursed. The tomb, probably not."

Thor lifts the lid anyway. Inside, the skeleton of a humanoid but definitely non-human creature clasps a glowing jewel to his chest with bony fingers.

He reaches in and removes the jewel, then replaces the lid.

"That doesn't look like a Silmaril."

"Uh, my Geiger counter says it is. It's definitely the gamma source I saw here."

"Thor—hit it as hard as you can with the hammer side of your weapon. If it's a Silmaril it'll be fine."

"'As hard as I can' is likely to make this room collapse on us."

"Yeah, let's not do that."

Thor puts the stone on the floor and hits it, not hard enough to bring down the room but hard enough to leave a crater in the stone floor, at the bottom of which is a smaller, differently faceted jewel glowing much more brightly than before, and shards of some other crystal.

Maglor picks up the Silmaril and one of the shards of crystal.

"It seems to have served as a seed crystal for common diamond in the mantle. Explains why it didn't burn all the mortals who touched it."

(The carbon that formed the diamond is plausibly the charred remains of his brother's body. He collects all the shards, intending to bury them as though they were.)

"Common diamond?"

"Yeah. It's just carbon. They're not...trivial to forge but we were doing it from almost our first days in Valinor—that's in fact what most of the sand on the public beach at Alqualondë was—little tiny ones."

(That he had later spilled blood on the same shores where he had once strewn gems, he does not mention.)

They put the second Silmaril in its own lead-lined box, climb back out of the Lonely Mountain, and fly back to New York.

They're greeted by a flying, armored elf.