The place where Dylan was held was called the Court of Bones, and it was the most heavily guarded prison in the Northern Land.
Those held here were, at the very least, heads of the Old Nobility, and even the selection criteria for the prison guards were nothing less than level five, which demonstrated the absurd extremes of its security.
Moreover, the Court of Bones itself was an independent module of the Great Floating City, Niglaiser, floating quietly like a Magic Cube beside the pitch-black Floating City.
As if it were designed to counter players who loved to explore sewers no matter where they invaded, a two-meter diameter pipe connected the prison to Niglaiser, bringing the prison's wastewater to the Great Floating City for centralized processing before disposal.
This not only eliminated the possibility of sneaking in through the back door but also extinguished the prisoners' hopes of escaping from there.