Had Liu Dezhu ever seen what was inside the Black Box? Indeed, he had not.
When he left Prison No. 10, the Mechanical Prison Guard, while returning the items confiscated before his incarceration, included the Black Box.
The Black Box looked ordinary, with a note stuck on it: "Do not open, hand it over to your boss."
The box wasn't locked, it didn't even have a simple combination lock, but Liu Dezhu truly never opened it to look inside.
From the moment he was released, he clung tightly to the Black Box, gripping it securely whether eating, sleeping, or dozing off.
This was confirmed by Yi.
In fact, it was a very simple test, if Liu Dezhu couldn't even do this, then his previously declared loyalty was certainly false.
Qing Chen needed a very small deed to verify whether Liu Dezhu had indeed become obedient.