Nobody Knows

June 3, 2020

Child welfare officer Cha Young-jin (Kim Seo-hyung) has never stopped investigating the unsolved murder of her childhood friend. Twenty years later, a new case suggests the same killer has struck again. The Nowon child welfare office establishes her professional world.

June 3, 2020

The similarities between the old murder and the new case are mapped. Young-jin's professional and personal investigation begins.

June 10, 2020

Investigation sequences in the older streets north of Seoul where the childhood crime and the present one connect.

June 10, 2020

The at-risk children Young-jin protects through her welfare work — the drama's most humanistic dimension.

June 17, 2020

Prosecutor Park Gun (Ryu Deok-hwan) is assigned the case. His methods and Young-jin's complement each other imperfectly.

June 17, 2020

Flashback sequences to the childhood friendship and the murder that ended it.

June 24, 2020

Young-jin's specific guilt — her survival when her friend did not — is examined.

June 24, 2020

The case's connection to an institutional cover-up becomes clear.

July 1, 2020

The killer's pattern across two decades — who they target, why, what they need.

July 1, 2020

The full story of the childhood friendship and its destruction.

July 8, 2020

Young-jin recognising a child at similar risk to her friend — and the drama's examination of what protection means.

July 8, 2020

The full extent of the institutional cover-up protecting the killer.

July 15, 2020

Young-jin and Park Gun closing in simultaneously on the killer and the cover-up.

July 15, 2020

A confrontation that has been twenty years in preparation.

July 22, 2020

The institutional accountability that Young-jin always wanted and the drama examines whether the system can deliver.

July 22, 2020

The finale. A well-crafted thriller that used its child welfare setting to examine institutional failure and the specific damage of unsolved childhood crimes.