The Silent Sea — Characters & Cast

Uncovering the truth behind the Balhae Station massacre and honoring her sister’s legacy.

Begins as a cold, emotionally detached ethologist traumatized by her sister’s mysterious death. Over the course of the mission, she transforms into a compassionate protector of Luna 073 and the ethical voice of the crew.

Securing high-tier water access to cure his terminally ill daughter, Ha-jin.

Starts as a stern military commander who strictly enforces orders and minimizes personal attachment. He evolves into a leader driven by moral conscience, ultimately giving his life so his team and Luna can survive.

Securing the Lunar Water sample for financial reward and escaping his past sins.

Appears as a polite, capable elite engineer who volunteered for the mission. He is revealed as a corporate mercenary working for the private conglomerate RX, driven by guilt over his past participation in the original Balhae military cover-up.

Saving human lives and upholding medical ethics.

Serves as the team’s pragmatic physician. Amid chaos and fatal infections, she adapts medical protocols to study Lunar Water and becomes an essential guardian for Dr. Song and Luna.

Ensuring the physical safety of the crew.

Remains a steadfast guardian who follows Captain Han’s command, defending the crew against internal betrayal until his fatal confrontation in the station.