In the basement of the agency, dazzling lights illuminated the newly built containment vault. The vault walls were made of metal mixed with a type of resin. Overall, they looked like walls formed from layers of iron wires as fine as strands of hair, with translucent resin poured inside them.
These were branches from bitter salt trees. Bitter salt trees only grew in the volcanic polar regions north of the continent. The reason their resin had been chosen as an insulating layer was the molten salt it contained.
Molten salt possessed a certain property: whenever energy or matter attempted to pass through it, it released an incredibly terrifying temperature. Although this lasted for only an instant, the heat was high enough to incinerate and vaporize most energy.
This was the highest temperature known to be achievable through artificial means. Unfortunately, because of molten salt's properties, it was extremely difficult to extract it from bitter salt tree resin.
Su Xiao sat on an iron chair inside the containment vault. The area covered more than three hundred square meters. At the center stood two glass pillars nearly three meters thick. One contained clear blue seawater, while the other held a faintly green, highly corrosive acid solution.
The mermaid imprisoned in a crystal coffin beside Su Xiao's feet was facing a choice: enter the glass pillar filled with seawater, or be thrown into the pillar filled with strong acid.
Su Xiao lowered his head and looked at the mermaid in the crystal coffin. She had a human torso and a fish tail, with long, bright-red hair covering her head. Her beautiful face and voluptuous figure fulfilled every man's fantasy.
But there was no need to imagine too much. The mermaid's mouth was filled with needle-like pointed teeth. The upper and lower rows added