Detective Hansaem suspects Ena after she fails to remember anything about her uncle's murder.
A puzzle piece arrives on the same day as a murder, and Hansaem suspects it’s no coincidence.
Ena and Hansaem warily work together to solve the case.
A prime suspect emerges, but things aren't what they seem.
Another puzzle piece arrives, and a new murder case unfolds.
The meaning behind the drawings on the puzzle pieces is uncovered.
Hansaem makes a shocking discovery and becomes unsure of whom to trust.
As the investigation escalates, new suspects begin to emerge.
An unexpected suspect is arrested, shocking everyone involved.
A stunning truth behind the serial murders is revealed.
The final puzzle piece arrives will the team be able to catch the killer in time?
