"I seem to remember a similar place, but why is there a city here?"
Istil's puzzled words instantly put Yang Yi and Su Na on the alert.
In tacit agreement, neither hurried her, giving Istil plenty of time to organize her thoughts and recount what she remembered.
"...You both know about concept levels. There are six in total: small, medium, large, enormous, immense, and great. It's a classification system used to describe special life-forms or items.
"But the actual classifications are measured by how much they distort 'common sense.'
"The great level is completely beyond reason. It cannot be analyzed, understood, or even observed.
"At first, it was impossible to determine whether these great-level entities even existed, so a great many were listed. Only later were they ruled out one by one, because some really were just legends or delusions.
"One of them was related to what you just mentioned..."
As Istil recalled the past, Su Na held her breath and secretly took notes. Some of this information concerned things even she had been uncertain about, and Istil had finally confirmed them.
"In my memory, the creature you call the Abyss Scavenger was actually an artificial life-form deliberately created and named the Collector.
"Its duty was to collect debris from the sea to exchange with the Greedy Hoarder.
"The so-called Greedy Hoarder wasn't a specific individual, but a rift into another dimension deep in the sea.
"What lay inside was unknown, because contact was lost with anything that entered, and nothing ever escaped. So, out of caution, it was classified as either great or immense at the time.
"In short, the rift accepted anything. Once a certain quantity of items had been put in and no more were added for a while, it would return an item, as though someone