After discovering the body of her murdered uncle, Yoon Ena becomes a profiler to uncover the truth behind what happened that night. A decade later, Detective Hansaem still suspects Ena was responsible, and when a series of murders begins to occur, each linked to a corresponding puzzle piece, Hansaem will follow his instincts to track down the killer.
E1
Detective Hansaem suspects Ena after she fails to remember anything about her uncle's murder.
E2
A puzzle piece arrives on the same day as a murder, and Hansaem suspects it's no coincidence.
E3
Ena and Hansaem warily work together to solve the case.
E4
A prime suspect emerges, but things aren't what they seem.
E5
Another puzzle piece arrives, and a new murder case unfolds.
E6
The meaning behind the drawings on the puzzle pieces is uncovered.
E7
Han Saem makes a shocking discovery and becomes unsure of whom to trust.
E8
As the investigation escalates, new suspects begin to emerge.
E9
In an unexpected twist, a new suspect is arrested shortly before another victim is discovered. E-na and Han-saem risk it all to try and catch the true killer.
E10
A stunning truth behind the serial murders is revealed.
E11
The final puzzle piece arrives. Will the team be able to catch the killer in time?