Zuo Jun's room was located within an "interlayer" of Tianshu Tower—viewed from outside, there was no indication that a room existed there at all, and the surrounding space was completely sealed off, with no passage connected to the outside world.
According to Tianshu Tower's blueprints, this area should originally have been part of the tower's load-bearing structure. Hollowing it out would have greatly reduced the building's stability... but that was only the conclusion one would reach through ordinary knowledge of architecture and materials science. For Tianshu Tower, hollowing out a load-bearing pillar and then using some "black technology" to preserve its original strength was nothing more than an exceedingly simple "research project."
Even the technical difficulty was far below that of entering the room.
The room had no windows, no doors, and no hidden passages. To enter it, one had to use a short-range teleportation device—or rather, an Anomaly Equipment item with short-range teleportation capabilities.
The Qualified User of this Anomaly Equipment was an operative from Tianshu Tower's secret security department. With a single thought from him, this room could become a "cell" completely cut off from the world.
Since it had been carved out within the load-bearing structure, the room itself was extraordinarily sturdy. According to Professor Cao, even if it endured repeated strategic nuclear bombardment, the people inside would not be harmed. If necessary, this section of the load-bearing structure could even sink directly underground and "dock" with the Primal Underground Palace.
"A prison no one can escape from?" As he stepped onto the short-range teleportation device, Sun Hang teasingly asked Professor Cao beside him.
"Not impossible to escape." Professor Cao shook his head, then let out a wine-scented burp. "At least, not for Number One."
"And he willingly lets you imprison him?"
"It isn't imprisonment either. In