For the Special Tactics Bureau, the fact ghouls could appear right in headquarters incited rage and shock.
Before, it was mentioned that the Bureau also had means to identify ghouls—of course, not as powerful as the Tribunal's Bird Divination Tool, but generally still quite useful.
That would be the RC detection gate.
Based on the Bureau's analysis of ghoul corpses, ghouls have a far higher concentration of something called RC cells within their bodies than humans, and in fact, ghouls consume humans precisely to absorb the RC cells within them.
Targeting this, the Bureau invented the RC detection gate, which scans everyone entering and exiting; should it find any presence of RC cells exceeding human standards, an alarm would naturally be triggered.
So what do you know, this green-haired woman walked back and forth through the detection gate and it didn't make a peep?
What use is this thing! Is it broken? Or is there a quality issue? Or is it simply a defective product?
