Han Feng watched the hooded figure from a distance.
The spy had begun moving through the forest, apparently preparing to leave.
Han Feng did not follow immediately.
Instead, he reached into his storage pouch and took out a tiny gray Gu.
The creature was no larger than a grain of rice. Its body was thin and almost transparent, with three tiny legs and a faint silver line running across its back.
The Tracewing Gu.
Han Feng had obtained it from the Black Moon Sect's outer resource hall. It was a low-rank tracking Gu, useful for following a single target for a limited period.
It wasn't powerful.
It couldn't transmit voices.
It couldn't see through walls.
And its connection would weaken with distance.
But it had one advantage.
If attached directly to a target, it could follow their spiritual signature for several hours.
Han Feng studied the spy carefully.
"I only get one chance."
He waited until the man passed beneath a thick tree.
A gust of wind swept through the branches.
At that exact moment, Han Feng flicked his finger.
The Tracewing Gu flew silently through the air.
It didn't attack the spy.
Instead, it landed on the back of his cloak, near the lower seam.
The insect immediately flattened its body and released a nearly invisible thread of spiritual energy.
The thread sank into the fabric.
Then disappeared.
The spy didn't react.
Han Feng closed his eyes.
A faint sensation appeared in his consciousness.
Direction.
Distance.
Movement.
Nothing more.
"It worked."
He didn't approach the target.
That would defeat the entire purpose.
Instead, Han Feng allowed the spy to gain distance before following.
He maintained a gap of several hundred meters, using the Tracewing Gu to determine the general direction.
Whenever the signal weakened, he stopped.
Whenever it strengthened, he continued.
This way, even if the spy turned around, Han Feng would have enough warning to conceal himself.
The chase continued into the night.
Eventually, the Tracewing Gu's signal led Han Feng toward a rocky cliff.
The spy disappeared behind the rocks.
Han Feng stopped.
He didn't move closer.
Instead, he waited.
After several minutes, the signal remained stationary.
"A cave."
Han Feng looked at the cliff.
There was no visible entrance from his position.
He carefully climbed to a higher point and discovered a narrow opening hidden beneath hanging vines.
The spy had entered through there.
Han Feng didn't follow.
The Tracewing Gu was still attached to the man's cloak.
As long as it remained undiscovered, Han Feng could wait and gather information.
He settled beneath a dead tree and concealed his aura with the Celestial Veil Art.
Then he waited for dawn.
But as the night grew colder, Han Feng noticed something troubling.
The connection with the Tracewing Gu was becoming weaker.
The stone around the cave was interfering with its spiritual signal.
He frowned.
"So even this method has limits."
That meant he couldn't depend on the tracker forever.
If he wanted answers, he would need another method.
And that was when Han Feng decided to use the Echo Listener Gu.
The hunt had changed.
He was no longer simply following the spy.
He was preparing to discover who the spy was working for.