It's raining heavily in Sin City.
Criminal police captain Zhou Jiming led a team to raid the gang's lair "Blue Whale", but only found a mysterious young man lying in a pool of blood-Chen Ge. His wrist was branded with a "blue whale" tattoo symbolizing the abyss, but he struggled to hand out the blood-stained USB flash drive, as angry as a gossamer:
"Tell Zhou Jiming... The password is his alarm number..."
His identity is a mystery and he is scarred. Is he the informant "Deep Blue" who guides the light, or is he a deadly bait sent by the abyss?
There is a turbulent undercurrent at the top of the police station. Deputy Director Lin Yi insists on severe punishment, but Zhou Jiming defies everyone's opinions and locks this dangerous mystery into his own safe house.
A hard-faced detective, a prisoner full of mysteries.
A prison that began with suspicion, a cooperation that wanders on the edge of hell.
When the bloody password in the USB flash drive is unlocked layer by layer, it points not only to the incriminating evidence, but also to the ferocious shadow under the police badge...
The deadly game of trust and betrayal quietly begins in the north of the city where the heavy rain has just stopped.
Purpose: Salute all great police officers