While investigating a perfect locked-room murder, criminal investigation captain Fu Chen discovers an old photograph from twenty years ago tucked into the victim's diary. The little boy in the background is none other than Fu Chen as a child. Even stranger, a puzzle piece appears at every new crime scene, and the pieces form a floor plan of the old Fu family residence.
Following the clues into his late father's study, he watches as a mummified corpse suddenly rolls out from inside the wall. The corpse wears a watch identical to Fu Chen's. According to the forensic report, its DNA is a close match for Fu Chen's, but it died in the year he graduated from university.
“Captain Fu, you were never investigating the killer,” says psychological expert Su Nian, handing him a bloodstained file. “You were investigating a false life that was implanted in you.”
On a stormy night, Fu Chen lifts the sheet in the morgue. A third “himself” lies quietly in the refrigerated drawer, this time a fresh corpse, with Su Nian's fountain pen sticking out of its chest.
The surveillance footage shows that the last person to enter the morgue was Fu Chen himself, carrying a cup of coffee.
