Underground base, the air was slowly flowing.
At the intersection of several corridors.
Ji Burlen continued to ponder how long it had been and how the person who had stealthily entered had managed to evade and disappear.
"Could it be Invisibility Technique? But it should be more effective to hide in a more complicated place. Using magic here, the effect wouldn't be good."
"Then, could it be some kind of disguise technique, shifting identities? No, the headcount hasn't changed."
"Could it be Earth Magic to enter underground? Wrong again, the ground here has been specially treated, making it difficult for Earth Magic to work."
Ji Burlen muttered to himself, voicing various possibilities and then rejecting each one, his brow furrowing tighter and tighter.
Ji Burlen kept thinking, the people standing around him dared not breathe too loudly, for fear of disturbing him, when suddenly an incongruous sound arose.
"Cough, cough!"
"Cough…cough cough!"
