There have been four "cement-sealed corpse cases" in Binjiang City in succession. The rusty ship nails in the palm of the deceased's right hand tore open the bloody scars from the "Qiming" shipwreck twenty years ago.
Jiang Lin, a trace detection expert, has a damaged right hand but can see through the fatal murder plot in the dust; Lu Ye, a criminal profiler, sketches the outline of the murderer, but cannot describe the last person his mother saw before she committed suicide. When the fourth corpse surfaced from the bottom of the aquarium's killer whale pool, the two were forced to face the cruelest truth:
The "underwater chamber" with frozen corpses embedded in flowing cement, the DNA files tampered with by the impostors, the ship nails that arrived as promised in the evidence room... Every piece of the bloody puzzle points to the ghost who should have died in the shipwreck.
The code Jiang Lin buried while undercover was engraved on the cabin where the murderer imprisoned the child; the antihypertensive drug dependence profiled by Lu Ye overlapped with the deep-sea diatoms behind the animal trainer's ears. The shipwreck distress signal reproduced by the real murderer is quietly resonating with the Morse code in Luye's mother's suicide call.
When the dam of lies collapsed and Jiang Lin clenched the murderer's syringe with his remaining hand, Lu Ye finally heard the string of abyss echoes that had lasted for twenty years - it turned out that one of them lived in the death faked by the other, and the other died in the truth concealed by the other.
"The sounds of keys inserting into keyholes mingled in the darkness. This time, one of them unlocked the sin and the other locked himself."
Concept: The sounds of keys inserting into keyholes intersected in the darkness. This time, one of them unlocked the sin and the other locked himself.