Every Spatial Folding left a permanent deformation in the fabric of spacetime. Even if the Folded Space itself had been destroyed, that crease would remain forever.
But such creases were exceedingly faint, so faint that ordinary methods could not detect them at all.
The Deduction Board spun for roughly twenty breaths.
Ye Changqing's brow twitched.
"North."
"How far?"
"Six hundred zhang. Underground... somewhere between seven hundred and a thousand zhang deep, there's a residual trace of Spatial Folding. Extremely faint, but it's definitely there."
"Are you sure it isn't something Zhao Ji left behind?"
"No. Zhao Ji's Blood Pool was three thousand zhang underground, toward the west. This is due north. Different depth, different direction."
Ye Changqing opened his eyes, and the light on the Deduction Board dimmed with them.
"And this folding trace is ancient. So ancient that my Deduction Board almost filtered it out as background noise."
"How ancient?"
"I can't determine that precisely, but a conservative estimate would put it at least five thousand years old."
Five thousand years.
The Extreme Bone Sect had been founded far longer ago than that.
Taiyi Divine Power erupted beneath Zhou Xuan's feet. He soared into the air and shot due north, with Ye Changqing following behind. Ye Changqing was somewhat slower, but did not fall too far behind.
The ground six hundred zhang away looked no different from anywhere else: rubble and scorched earth, with nothing unusual in sight.
Zhou Xuan landed, poured Taiyi Divine Power into his feet, and probed downward.
Seven hundred zhang, seven hundred and fifty, eight hundred.
At a depth of eight hundred and twenty zhang, his Taiyi Divine Power touched something unusual.
It was neither rock nor soil, but an extremely thin, almost imperceptible membrane of energy. It was so thin it seemed ready to