When criminal lawyer Shen Li pulled out the same piece of faded blue cloth from the corpse of the rich man in the "suicide case" from the fingertips of the scene where his father died in the line of duty, the "Lighthouse Case" that had been covered in dust for ten years turned into an evil beast and tore off its disguise. She followed the blood trail into the abyss, only to bump into the man who had died long ago in the old case - Lu Chen. He is an intelligence dealer who travels in black and white, a business upstart who controls the dark river, and he is the answer to the sentence "Protection Key No. 7" In his father's suicide note.
Intention: Who can see clearly what is true and what is false?