Korra and Asami, and it's empty.

"So, is Tenzin still mad about the joke you helped Meelo pull?" Asami asked Korra as they took a leisurely stroll around the island.

"Ugh, I don't think I've ever seen him that pissed off. I didn't think the glitter bombs would be that bad... But as it turns out, glitter is pure evil," Korra shuddered.

"You'd think with so many Airbenders around, it would be easy to get rid of, but they're still finding it everywhere, huh?" Asami giggled.

"And how!" Korra laughed, wrapping an arm around her girlfriend. "It's worse than sand, it gets in every nook and cranny you can think of! And many you wouldn't! Last time I let Meelo rope me into helping him pull a practical joke involving the stuff, it was not worth it."

"Not like you could have known, it's a fairly new invention," Asami remarked. Her foot then impacted something, and they looked down to see the golden lamp, gleaming in the sun.

"Huh, is someone dumping things on the island?" Korra asked, a bit irritated at the thought, even as she picked the lamp up.

"Doubt it, this looks too fancy for someone to just toss. It's definitely not garbage..." Asami mused, looking it over. She knew gold when she saw it, having grown up in luxury.

(As a custodian, I can confirm. Glitter is pure evil, and there's a special place in hell for whoever invented it.)