"There's no such thing as Sadde, there's no such thing as Sadde!" he sing songs back.

He giggles. "Sadde is a concept, an idea, something too complex for you to understand."

Eventually, they reach the ruins, massive and inhuman. 

"Ooooh." He goes exploring with his flippers.

"Whoever made these were silly."

"Why? They're cool! And so big!"

"Who needs a creepy castle underwater?"

"I dunno. Aliens? Weird mer?"

"Mer woudn't like it down here."

"I dunno, then. Is there any tech here?"

None that is readily apparent. There are a lot of perverse looking statues, though.

Perverse how?

Bizarre, completely inhuman. Somewhat malevolent looking.

"Are these the aliens?"

"Maybe, or they could be different aliens. Or something that lived on Earth before people."

"Your Earth is weird."

"Why? Do you not have aliens?"

"Well maybe Scion's an alien but he won't tell anyone if he is."

"Is that the floaty guy who is like Mum but weird?

"Yeah. He's also made of gold."

"Like Maurice when he's embarrassed?"

"I dunno, never seen him embarrassed."

"I can never make sense of his skin."

"Scion is all gold, even the eyes. He was naked when he appeared, too, so he was all gold, really."

"You ever met him?"