Bab 167: 167: The real reason

"If you hadn't interfered with its escape, it would've been captured as it's not native to the Abyss," Voidslayer promptly replied.

"Captured by whom?" Val asked, "And how does it getting captured endanger me?" 

"I was getting to that point," Voidslayer said, "Before I give you the answers, there is something you should know."

"What is it?" Val asked.

Voidslayer replied, "I told you that the expedition to Abyss was banned because of the danger it posed, but I forgot to mention that although the Abyss was barely explored and its entrances were sealed just a few months after the first expedition, the Wizards of Old made an entire textbook about it by correlating stories about the time they spend in the Abyss. 

"It's said that Abyss is infinitely large and unlike our world, it's not round but flat with five regions. Different wells led to different regions, yet no matter what region they ended up in, they all experienced being hunted by Mindflayers."