The Silent Sea summary and ending explained

The Silent Sea follows a group of space explorers on a 24 hour mission to a research center on the moon as they are tasked with the retrieval of an undisclosed sample. The 8 part series is now streaming on Netflix.


In a futuristic dystopian world where the land is barren and there is immense water scarcity, government and private corporations are trying to come up with methods to reduce water usage and the laymen are protesting against supply regulations as inequalities in the access of water has intensified.

Dr. Song Ji-an (Bae Doona) a former astrobiologist is approached by the SAA to be a part of a mission to the Balhae Lunar Research Centre where five years back 117 crew members died due to a radiation leak. One of the crew members who lost their lives in that tragic event was her sister, and hence she was given a gold card that gives her access to water easily as compensation.

She agrees to be a part of the 10 member crew that includes Captain Han Yoon-jae (Gong Yoo), Ryoo Tae-seok (Lee Joon) and Hong Ga-young (Kim Sun-young) among others. As the mission is being explained to the crew, Dr. Song starts having many questions as only very little information is disclosed to them. But the captain dismisses her saying, “we just have to do as we are told.” They have been tasked with the retrieval of an important sample in a 24-hour mission before closing the station permanently and returning to earth.

As the team sets to move, they realize that the co-pilot has been switched and this makes everyone a little skeptical. Due to a system failure they are required to do an emergency landing which proves to be fatal for one of the crew members. The spacecraft starts to dip as it’s on the edge of a cliff but everyone manage to escape in the nick of time. However, the injured crew member passes away saying, “the water, don’t.”

Everyone gets inside the station just before their oxygen runs out and as they walk around they discover a body whose cause of death seems to be drowning. This puzzles them but what seems to be more confusing is the normal levels of radiation in the station. Dr. Song insists that they investigate the cause of death of the body they found as now it was clear that radiation leaks were not responsible for it.

After understanding the layout of the station and allocating areas they move forward to find the samples from the three storages. In the search, some of them find more bodies and the co-pilot gets attacked and killed by something unknown which also takes the sample with it. Yet another crew member seems to be infected by some kind of virus that is causing him to vomit water uncontrollably. They are unable to report all these eerie things happening in the station to the officials back in earth as all the comms are down.

Through the presence of an unknown signal which is later identified as being the co-pilot’s secret device, they contact the officials and ask for a rescue ship but the mission is delayed as now they are tasked with not only retrieving the samples but also finding and killing the intruder. They also find out that the sample they have come to retrieve is water, water that multiplies which could solve all the problems back in earth. After discovering a secret storage filled with greenery they realize that if they are able to control this multiplying water they’d have all the water mankind would ever need.

Wherever they find the sample of lunar water the intruder who is a little girl shows up. The lunar water helps her heal and also gives her inhuman physical abilities as she is the only survivor of the many experiments conducted by the crew five years back on little girls. Her body also seems to produce antibodies which doesn’t allow the lunar water to multiply uncontrollably in other humans as well.

In-between all this, a crew member named Ryoo Tae-seok goes rogue and starts killing other crew members. Even he seems to be working for the Resource Exploration for Space Mining and Planetary Development (RX) as the co-pilot.

What emotional reasons do Captain Han and Dr. Song have for being on this mission? What happens to the little girl? Why is Ryoo Tae-seok working for the RX? If you still have all these questions, here is a detailed breakdown for you.

The Silent Sea ending explained (Episode 8: The Silent Sea)


Dr. Song’s sister worked as the chief researcher at the Balhae station and was one of those who lost their lives five years back. Before dying she sends Dr. Song a message, “Find Luna” and this is the main reason she agrees to be a part of this mission.

This is also why she wants to protect Luna and take her to The International Institute of Space Biology as she thinks it is a more neutral place where the research can continue.

Captain Han’s daughter is sick and there is nothing more the doctors can do as he is in a lower water access level. He wants to save his daughter and this mission might be his only hope, so he agrees.

At first he doesn’t mind experiments being done on Luna for the greater good but later he sees his own daughter in her and even gives Luna a badge with his daughter’s sticker on it.

Ryoo Tae-seok and RX

Ryoo Tae-seok was a member of the Ministry of National Defense whose mission was to close Balhae Station. Their job was to close the station leaving hundreds of crew members there to die.

This incident mentally affected him and he was consumed by guilt. So he decided to work for the Resource Exploration for Space Mining and Planetary Development (RX), which is considered to be an enemy of the government.

Even as he dies, he apologises.


As the remaining survivors are leaving the station which gets flooded by lunar water, Captain Han realises that the gates have to be manually opened. He stays behind sacrificing his life to let the others, Dr. Song, Doc Hong and Luna escape the station in time.

Luna runs into the space without a space suit and is able to breathe and roam around freely. As she sees Captain Han, who has been thrown out of the station due to the water pressure, she tries to return his badge.

He doesn’t take it but is happy to see that Luna has survived and so the mission has been completed. The rescue ship arrives and we can only assume that the three lone female survivors board it and reach earth safely.

Also Read: Don’t Look Up (2021) summary and ending explained

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