The suspected petty thief crawling a few dozen meters ahead of Perfect Baldhead had indeed failed to notice the movement behind him.
That had little to do with Perfect Baldhead's efforts to move quietly... the bumps and crashes he made while crawling through broken walls and shattered tiles only a few dozen centimeters high would have drawn plenty of attention under normal circumstances.
But that was under normal circumstances.
Now, terrifying explosions and roars reverberated through this sealed underground cavern... and every one of them echoed.
Never mind Perfect Baldhead occasionally bumping into a wall or knocking his head—even if he charged recklessly forward, he might not have caught the petty thief's attention.
Besides, although the petty thief had learned a few rogue tricks, he was still a spellcaster. Whoever was directing him was hardly going to give him genuine techniques for changing classes or taking a second class, either. His alertness might well have been worse than that of an ordinary Undead rogue.
That was understandable, though.
In the world of mages, there was no need to worry about how quietly a snooper moved or how good he was at slipping through walls. Warding and isolation formations could solve most problems.
All he needed to do was conceal his presence as best he could while spying on information from his own side... as long as the people above him did not question his identity, there was nothing wrong with him appearing somewhere he was already allowed to be.
Level-zero rogue skills, such as moving quietly, were all he needed.
As for skills that directly increased perception, such as sensing when someone was watching him, the mastermind behind him certainly would not teach him those.
The higher someone's perception, the easier it was for them to discern whether the emotions