Hansaem makes a shocking discovery and becomes unsure of whom to trust.

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.

The meaning behind the drawings on the puzzle pieces is uncovered.

As the investigation escalates, new suspects begin to emerge.

Another puzzle piece arrives, and a new murder case unfolds.

Detective Hansaem suspects Ena after she fails to remember anything about her uncle's murder.

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?