"Don't panic." Zhang Ze didn't check the prison cell but instead took out a tool that resembled a compass.
The round compass was divided into inner and outer layers; the inner layer was no different from an ordinary compass, while the outer layer contained some kind of liquid, with a tuft of light blue mycelium floating quietly inside.
Zhang Ze activated the compass with Spiritual Qi, and the mycelium twitched, then began to spin within the ring, finally stopping at a certain direction, which, according to the inner part of the compass, pointed west of the city.
How Qiu Jidan escaped didn't matter; knowing where he was now was enough.
This thing was a new toy Fuji gave Zhang Ze before he set out, which allowed him to use Fuji's unique principle of mycelium attraction for secret remote tracking in Fuji's absence.
Zhang Ze had hidden a bit of this mycelium in Qiu Jidan's hair when he tucked him in.