```
Clang, clang, clang...
The half-meter-thick alloy metal door slowly closed, embedding itself onto the underground tracks and emitted a dull sound, finally sealing shut with a loud bang.
At the door, Siegel and Thomas looked at each other.
"Are we really going to let this boss do as he pleases?"
Siegel hesitated for a moment before asking the question. It wasn't that he didn't trust Casio's strength, but the four convicts on the third underground level of the Beast's Lair were truly ferocious--the felons among felons. Criminals who had killed more than a dozen people were nothing compared to them, and if even one of them got out, they could go on a killing spree in Emerald City, taking tens of thousands of lives. Don't be fooled by their appearance of being able to communicate, and even Siegel's master Otto occasionally helping out. But in reality, their consciousness had been completely twisted, having drastically transformed into the instinctual nature of dark creatures.
