Black Prison was the prison the Wizard Alliance used to hold captured demons.
Although the vast majority of demons were killed by wizards during hunts, some always survived for one reason or another: special abilities, unusual bloodlines, particular information they possessed, or simply sheer luck, among other things.
All these living demons were locked up in Black Prison by the wizards.
Even when a wizard's magical research required living demons, they could only use the separate, fully sealed laboratories established inside Black Prison. Under First University's laboratory safety regulations, no living demon was permitted in any laboratory outside Black Prison—which was why the appearance of a wild demon on campus had triggered a red alert and ultimately led to a series of disciplinary actions and personnel transfers.
But Black Prison was no retirement home.
Demons sent into Black Prison would never live long enough to die of old age. Meanwhile, demons captured outside continued to pour into the prison, day after day. As a result, an enormous number of demon corpses had accumulated there.
Some corpses had unusual bloodlines or were in good condition and could still be salvaged by the wizards. Many others, however, had very little salvage value because they were mangled, in poor condition, or simply of little practical use.
"...That ancient tree was Black Prison's ultimate solution for recycling demon corpses." The captain of the Mist looked past the female demon's shoulder, out the window at the boundless sea. His voice grew increasingly grave. "Every few centuries, once that tree has 'had its fill,' it flowers and bears a few fruits. Those fruits aren't much use to wizards, but to demons, especially high-ranking demons, they hold an irresistible allure..."
At this, Nikita involuntarily held her breath.
This was not the first time she had heard of